bitmap: fix opencoded bitmap_allocate_region()

bitmap_find_region() opencodes bitmap_allocate_region().

CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Yury Norov <yury.norov@gmail.com>

lib/bitmap.c

@@ -803,10 +803,8 @@ int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order)
 	unsigned int pos, end;		/* scans bitmap by regions of size order */
 
 	for (pos = 0; (end = pos + BIT(order)) <= bits; pos = end) {
-		if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
-			continue;
-		__reg_op(bitmap, pos, order, REG_OP_ALLOC);
-		return pos;
+		if (!bitmap_allocate_region(bitmap, pos, order))
+			return pos;
 	}
 	return -ENOMEM;
 }