libc/glibc: fix installing syscall.h when installing start-files.

Reported-by: Rafael C <groups.r2@gmail.com>
Reported-by: Jérôme BARDON <bardon.pro@gmail.com>
Reported-by: Daniel Price <daniel.price@gmail.com>
[yann.morin.1998@free.fr: use a conditional approach, also suggested by Daniel]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 #!/bin/sh

 # Needed for systems without gettext

 $* -xc -o /dev/null - > /dev/null 2>&1 << EOF

 #include <libintl.h>

 int main()

 {

 	gettext("");

 	return 0;

 }

 EOF

 if [ ! "$?" -eq "0"  ]; then

 	echo -DKBUILD_NO_NLS;

 fi