lib/test_bitmap.c: add test for bitmap_cut()

Inspired by an original patch from Yury Norov: introduce a test for
bitmap_cut() that also makes sure functionality is as described for
partially overlapping src and dst.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Yury Norov <yury.norov@gmail.com>
Link: http://lkml.kernel.org/r/5fc45e6bbd4fa837cd9577f8a0c1d639df90a4ce.1592155364.git.sbrivio@redhat.com


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>