GFS2: Move gfs2_sync_meta to lops.c

Since gfs2_sync_meta() is only called from a single file, lets move
it to lops.c where it is used, and mark it static. At the same
time, we can clean up the meta_io.h header too.

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

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

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

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