62c1740676 changed the location of the script from $(TOOLCHAIN_DIR)/usr
to $(TOOLCHAIN_DIR), but the TOOLCHAIN_SYSROOT used in wrapper.sh was
still expecting to find the script under usr/bin.
Fixes: 62c1740676 toolchain: fix the sysroot mess by getting...
Signed-off-by: Eneas U de Queiroz <cotequeiroz@gmail.com>