[GFS2] Merge bits.[ch] into rgrp.c

Since they are small and will be inlined by the complier,
it makes sense to merge the contents of bits.[ch] into
rgrp.c

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --cc fs/gfs2/bits.c
Simple merge

diff --cc fs/gfs2/bits.h
Simple merge

diff --cc fs/gfs2/rgrp.c
Simple merge