[GFS2] mark struct *_operations const

these struct *_operations are all method tables, thus should be const.

Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

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

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

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