gfs2: gfs2_ail_empty_gl no log flush on error

Before this patch, function gfs2_ail_empty_gl called gfs2_log_flush even
in cases where it encountered an error. It should probably skip the log
flush and leave the file system in an inconsistent state, letting a
subsequent withdraw force the journal to be replayed to reestablish
metadata consistency.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glops.c

@@ -132,8 +132,9 @@ static int gfs2_ail_empty_gl(struct gfs2_glock *gl)
 	gfs2_trans_end(sdp);
 
 flush:
-	gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
-		       GFS2_LFC_AIL_EMPTY_GL);
+	if (!ret)
+		gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
+				GFS2_LFC_AIL_EMPTY_GL);
 	return ret;
 }