[GFS2] Remove one typedef

This removes one of the typedefs from the locking interface. It
is replaced by a forward declaration of the gfs2 superblock. The
other two are not so easy to solve since in their case, they
can refer to one of two possible structures.

Cc: David Teigland <teigland@redhat.com>
Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/locking/dlm/thread.c b/fs/gfs2/locking/dlm/thread.c
index d4895ec..554bf88 100644
--- a/fs/gfs2/locking/dlm/thread.c
+++ b/fs/gfs2/locking/dlm/thread.c
@@ -41,7 +41,7 @@
 		gdlm_assert(0, "unknown bast mode %u", lp->bast_mode);
 	}
 
-	ls->fscb(ls->fsdata, cb, &lp->lockname);
+	ls->fscb(ls->sdp, cb, &lp->lockname);
 }
 
 static void process_complete(struct gdlm_lock *lp)
@@ -232,7 +232,7 @@
 	    (lp->cur > DLM_LOCK_NL) && (prev_mode > DLM_LOCK_NL))
 		acb.lc_ret |= LM_OUT_CACHEABLE;
 
-	ls->fscb(ls->fsdata, LM_CB_ASYNC, &acb);
+	ls->fscb(ls->sdp, LM_CB_ASYNC, &acb);
 }
 
 static inline int no_work(struct gdlm_ls *ls, int blocking)
@@ -318,7 +318,7 @@
 			gdlm_do_lock(lp);
 
 		if (drop)
-			ls->fscb(ls->fsdata, LM_CB_DROPLOCKS, NULL);
+			ls->fscb(ls->sdp, LM_CB_DROPLOCKS, NULL);
 
 		schedule();
 	}