ocfs2: use swap() in dx_leaf_sort_swap()

Use kernel.h macro definition.

Thanks to Julia Lawall for Coccinelle scripting support.
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/dir.c

@@ -3543,13 +3543,10 @@ static void dx_leaf_sort_swap(void *a, void *b, int size)
 {
 	struct ocfs2_dx_entry *entry1 = a;
 	struct ocfs2_dx_entry *entry2 = b;
-	struct ocfs2_dx_entry tmp;
 
 	BUG_ON(size != sizeof(*entry1));
 
-	tmp = *entry1;
-	*entry1 = *entry2;
-	*entry2 = tmp;
+	swap(*entry1, *entry2);
 }
 
 static int ocfs2_dx_leaf_same_major(struct ocfs2_dx_leaf *dx_leaf)