afs: Get rid of afs_call::reply[]

Replace the afs_call::reply[] array with a bunch of typed members so that
the compiler can use type-checking on them.  It's also easier for the eye
to see what's going on.

Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/flock.c

@@ -74,7 +74,7 @@ static void afs_schedule_lock_extension(struct afs_vnode *vnode)
  */
 void afs_lock_op_done(struct afs_call *call)
 {
-	struct afs_vnode *vnode = call->reply[0];
+	struct afs_vnode *vnode = call->xvnode;
 
 	if (call->error == 0) {
 		spin_lock(&vnode->lock);