bitops: Use non-bitops ctzl

The use of ctz has already eliminated zero, and thus the difference
in edge conditions between the two routines is irrelevant.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

util/bitops.c

@@ -60,7 +60,7 @@ found_first:
         return result + size;	/* Nope. */
     }
 found_middle:
-    return result + bitops_ctzl(tmp);
+    return result + ctzl(tmp);
 }
 
 /*