GFS2: Misc fixes

Some items picked up through automated code analysis. A few bits
of unreachable code and two unchecked return values.

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

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

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

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