gfs2: Fixup to "Get rid of flush_delayed_work in gfs2_evict_inode"

When commit 4fd1a579 moved the call to flush_delayed_work from
gfs2_evict_inode to gfs2_inode_lookup to avoid calling into DLM during
evict, a similar call should have been added to gfs2_create_inode:
that's another code path in which glocks of previous inodes may be
reused.

The flush of the iopen glock work queue added by 4fd1a579, on the
other hand, is unnecessary and can be removed.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>