grub-install: Locale depends on nls

grub-install: Locale depends on nls

With --disable-nls no locales exist.

Avoid runtime error by moving code that copies locales into its own
function. Return early in case nls was disabled. That way the compiler
will throw away unreachable code, no need to put preprocessor
conditionals everywhere to avoid warnings about unused code.

Fix memleak by freeing srcf and dstf.
Convert tabs to spaces in moved code.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>