gfs2: Initialize gh_error in gfs2_glock_nq

The gh_error field if a glock holder is initialized to zero in
gfs2_holder_init().  When a locking operation fails, gh_error is set to
an error code; when it succeeds, the gh_error value is left unchanged.
The field isn't initialized in gfs2_holder_reinit(), which is a problem.
Instead of fixing that directly, initialize gh_error in gfs2_glock_nq().
That also obsoletes the assignment in do_flock().
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/file.c

@@ -1497,7 +1497,6 @@ static int do_flock(struct file *file, int cmd, struct file_lock *fl)
 		if (error != GLR_TRYFAILED)
 			break;
 		fl_gh->gh_flags = LM_FLAG_TRY | GL_EXACT;
-		fl_gh->gh_error = 0;
 		msleep(sleeptime);
 	}
 	if (error) {

fs/gfs2/glock.c

@@ -1261,7 +1261,6 @@ void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags,
 	gh->gh_owner_pid = get_pid(task_pid(current));
 	gh->gh_state = state;
 	gh->gh_flags = flags;
-	gh->gh_error = 0;
 	gh->gh_iflags = 0;
 	gfs2_glock_hold(gl);
 }
@@ -1567,6 +1566,7 @@ int gfs2_glock_nq(struct gfs2_holder *gh)
 	if (test_bit(GLF_LRU, &gl->gl_flags))
 		gfs2_glock_remove_from_lru(gl);
 
+	gh->gh_error = 0;
 	spin_lock(&gl->gl_lockref.lock);
 	add_to_queue(gh);
 	if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) &&