functions: fix date calculations

In case date(1) does not support nanosecond resolution, it does
not interpret '%N', and leave it as-is. So we have to remove it.

Note that some versions replaces '%N' with 'N', so we have to
take this into account as well.

Reported-by: Kyle Grieb <grieb.kyle@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
(transplanted from bb6e2df2427f3db871721c96ca3226cfa24204bc)

#!/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