scripts: update distclean

The toolchains are now built in .build/ rather than in targets/
so distclean has to get rid of that.

We also clean up the old dir, as users may have old samples that
still refer to the old location.

Do not hide messages during distclean, and do not ignore errors.

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