ltq-adsl-app: Fix compilation with GCC 14

This fixes the following compile problem:
```
checking for asm/types.h... dsl_cpe_linux.c: In function 'DSL_CPE_ThreadInit':
dsl_cpe_linux.c:779:25: error: assignment to 'DSL_CPE_Thread_t' {aka 'int'} from 'pthread_t' {aka 'struct __pthread *'} makes integer from pointer without a cast [-Wint-conversion]
  779 |          pThrCntrl->tid = tid;
      |                         ^
dsl_cpe_linux.c: In function 'DSL_CPE_ThreadDelete':
dsl_cpe_linux.c:862:44: error: passing argument 1 of 'pthread_cancel' makes pointer from integer without a cast [-Wint-conversion]
  862 |             switch(pthread_cancel(pThrCntrl->tid))
      |                                   ~~~~~~~~~^~~~~
      |                                            |
      |                                            DSL_CPE_Thread_t {aka int}
In file included from dsl_cpe_linux.h:35:
/builder/shared-workdir/build/staging_dir/toolchain-mips_mips32_gcc-14.2.0_musl/include/pthread.h:98:20: note: expected 'pthread_t' {aka 'struct __pthread *'} but argument is of type 'DSL_CPE_Thread_t' {aka 'int'}
   98 | int pthread_cancel(pthread_t);
      |                    ^~~~~~~~~
dsl_cpe_linux.c: In function 'DSL_CPE_ThreadIdGet':
dsl_cpe_linux.c:1123:11: error: returning 'pthread_t' {aka 'struct __pthread *'} from a function with return type 'DSL_CPE_Thread_t' {aka 'int'} makes integer from pointer without a cast [-Wint-conversion]
 1123 |    return pthread_self();
      |           ^~~~~~~~~~~~~~
```

While at it, fix also some additional build warnings.

--- a/src/dsl_cpe_linux.h
+++ b/src/dsl_cpe_linux.h
@@ -21,7 +21,7 @@
 #include <stdlib.h>
 #include <getopt.h>
 #include <stdio.h>               /* fdopen */
-#include <sys/fcntl.h>           /* open */
+#include <fcntl.h>               /* open */
 #include <sys/ioctl.h>           /* ioctl */
 #include <string.h>              /* memset, strstr, strlen */
 #include <stdlib.h>              /* strtoul */
@@ -233,7 +233,7 @@ typedef struct stat              DSL_CPE
 /**
    LINUX User Thread - map the Thread ID.
 */
-typedef int    DSL_CPE_Thread_t;
+typedef pthread_t    DSL_CPE_Thread_t;
 
 /**
    LINUX User Thread - function type LINUX User Thread Start Routine.
--- a/src/dsl_cpe_os_lint_map.h
+++ b/src/dsl_cpe_os_lint_map.h
@@ -168,7 +168,7 @@ typedef struct timeval           DSL_Tim
 /**
    LINUX User Thread - map the Thread ID.
 */
-typedef int    DSL_CPE_Thread_t;
+typedef pthread_t    DSL_CPE_Thread_t;
 
 /**
    LINUX User Thread - function type LINUX User Thread Start Routine.
--- a/src/dsl_cpe_control.c
+++ b/src/dsl_cpe_control.c
@@ -2062,7 +2062,7 @@ DSL_Error_t DSL_CPE_ScriptExecute (
 
       /* if the line is empty or a special "#" symbol detected,
          then go on to the next */
-      if ((sscanf (buf, "%s", &str_command) == 0) || (buf[0] == '#'))
+      if ((sscanf (buf, "%s", str_command) == 0) || (buf[0] == '#'))
       {
          continue;
       }
@@ -2075,7 +2075,7 @@ DSL_Error_t DSL_CPE_ScriptExecute (
 
       while(*pFile__++ != '\n');
 
-      if ((sscanf (buf, "%s", &str_command) == 0) || (buf[0] == '#'))
+      if ((sscanf (buf, "%s", str_command) == 0) || (buf[0] == '#'))
       {
          continue;
       }
@@ -2269,7 +2269,7 @@ DSL_Error_t DSL_CPE_ScriptExecute (
       {
          meireg regrdwr;
 
-         sscanf (buf, "%s %s %s", &str_command, &op1, &op2);
+         sscanf (buf, "%s %s %s", str_command, &op1, &op2);
          regrdwr.iAddress = strtoul (op1, DSL_NULL, 0) + MEI_SPACE_ACCESS;
 
 
@@ -2302,7 +2302,7 @@ DSL_Error_t DSL_CPE_ScriptExecute (
       {
          meireg regrdwr;
 
-         sscanf (buf, "%s %s %s", &str_command, &op1, &op2);
+         sscanf (buf, "%s %s %s", str_command, &op1, &op2);
          regrdwr.iAddress = strtoul (op1, DSL_NULL, 0) + MEI_SPACE_ACCESS;
          if (ioctl (pContext->fd, DANUBE_MEI_CMV_READ, &regrdwr) < 0)
          {
@@ -3522,7 +3522,7 @@ DSL_CPE_STATIC  DSL_int_t DSL_CPE_Event_
          sprintf(sVarName, "DSL_DATARATE_%s_BC%d",
             pEvent->data.nAccessDir == DSL_DOWNSTREAM ? "DS" : "US",
             pEvent->data.nChannel == 0 ? 0 : pEvent->data.nChannel == 1 ? 1 : 0);
-         sprintf(sVarVal, "%lu", pEvent->data.pData->channelStatusData.ActualDataRate);
+         sprintf(sVarVal, "%u", pEvent->data.pData->channelStatusData.ActualDataRate);
 
          if (DSL_CPE_SetEnv(sVarName, sVarVal) == DSL_SUCCESS)
          {