lib: bitmap: micro-optimize bitmap_allocate_region

__reg_op(..., REG_OP_ALLOC) always returns 0, so we might as well use that
and save an instruction.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/bitmap.c b/lib/bitmap.c
index c2f3807..faaf720 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -1154,8 +1154,7 @@
 {
 	if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE))
 		return -EBUSY;
-	__reg_op(bitmap, pos, order, REG_OP_ALLOC);
-	return 0;
+	return __reg_op(bitmap, pos, order, REG_OP_ALLOC);
 }
 EXPORT_SYMBOL(bitmap_allocate_region);