ocfs2: Move 'wanted' into parens of ocfs2_resmap_resv_bits.

The first time I read the function ocfs2_resmap_resv_bits, I consider
about what 'wanted' will be used and consider about the comments.
Then I find it is only used if the reservation is empty. ;)

So we'd better move it to the parens so that it make the code more
readable, what's more, ocfs2_resmap_resv_bits is used so frequently
and we should save some cpus.
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/reservations.c

@@ -732,25 +732,23 @@ int ocfs2_resmap_resv_bits(struct ocfs2_reservation_map *resmap,
 			   struct ocfs2_alloc_reservation *resv,
 			   int *cstart, int *clen)
 {
-	unsigned int wanted = *clen;
-
 	if (resv == NULL || ocfs2_resmap_disabled(resmap))
 		return -ENOSPC;
 
 	spin_lock(&resv_lock);
 
+	if (ocfs2_resv_empty(resv)) {
 		/*
 		 * We don't want to over-allocate for temporary
 		 * windows. Otherwise, we run the risk of fragmenting the
 		 * allocation space.
 		 */
-	wanted = ocfs2_resv_window_bits(resmap, resv);
+		unsigned int wanted = ocfs2_resv_window_bits(resmap, resv);
+
 		if ((resv->r_flags & OCFS2_RESV_FLAG_TMP) || wanted < *clen)
 			wanted = *clen;
 
-	if (ocfs2_resv_empty(resv)) {
 		mlog(0, "empty reservation, find new window\n");
-
 		/*
 		 * Try to get a window here. If it works, we must fall
 		 * through and test the bitmap . This avoids some