GFS2: fix recursive locking during rindex truncates

When you truncate the rindex file, you need to avoid calling gfs2_rindex_hold,
since you already hold it.  However, if you haven't already read in the
resource groups, you need to do that.

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

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

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

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