toolchain: fix dangling symlink to self in FixupLibdir

This avoids a dangling symlink to self when reinstalling the toolchain:

./staging_dir/toolchain-mips_24kc_gcc-9.3.0_musl/lib/lib -> lib

This is caused by the fact that in the toolchain dir we have

'lib64 -> lib'

and on executing

'ln lib ./staging_dir/toolchain-mips_24kc_gcc-9.3.0_musl/lib64'

ln dereference the symbolic link 'lib64' to 'lib' so the REAL command is

'ln lib ./staging_dir/toolchain-mips_24kc_gcc-9.3.0_musl/lib'

this results in the dangling symlink to self.

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
[ add more details to the commit description and fix title ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>

include/toolchain-build.mk

@@ -18,6 +18,6 @@ define FixupLibdir
 		mkdir -p $(1)/lib; \
 		mv $(1)/lib64/* $(1)/lib/; \
 		rm -rf $(1)/lib64; \
+		ln -sf lib $(1)/lib64; \
 	fi
-	ln -sf lib $(1)/lib64
 endef