Extend tools bitmap API with bitmap_equal() implementation.

The implementation has been derived from the kernel.

Extend tools bitmap API with bitmap_free() implementation for symmetry
with bitmap_alloc() function.
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/43757993-0b28-d8af-a6c7-ede12e3a6877@linux.intel.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>