staging: lustre: libcfs: Use swap() in cfs_hash_bd_order()

Use swap() function instead of using a temporary variable for swapping
two variables.

The Coccinelle semantic patch used to make this change is as follows:
//<smpl>
@@
type T;
T a,b,c;
@@
- a = b;
- b = c;
- c = a;
+ swap(b, c);
//<smpl>

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/libcfs/hash.c

@@ -803,12 +803,8 @@ cfs_hash_bd_order(struct cfs_hash_bd *bd1, struct cfs_hash_bd *bd2)
 	if (rc == 0) {
 		bd2->bd_bucket = NULL;
 
-	} else if (rc > 0) { /* swab bd1 and bd2 */
-		struct cfs_hash_bd tmp;
-
-		tmp = *bd2;
-		*bd2 = *bd1;
-		*bd1 = tmp;
+	} else if (rc > 0) {
+		swap(*bd1, *bd2); /* swap bd1 and bd2 */
 	}
 }