config/toolchain: hide sysroot name when in backend mode

In backend mode, setting the sysroot name is the
responsibility of the upper-layer build system.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.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