md: Simplify sb_equal().

The only caller of sb_equal() tests the return value against
zero, so it's OK to return the negated return value of memcmp().

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 8a03c95..20e03db 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -572,11 +572,7 @@
 	tmp1->nr_disks = 0;
 	tmp2->nr_disks = 0;
 
-	if (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4))
-		ret = 0;
-	else
-		ret = 1;
-
+	ret = (memcmp(tmp1, tmp2, MD_SB_GENERIC_CONSTANT_WORDS * 4) == 0);
 abort:
 	kfree(tmp1);
 	kfree(tmp2);