dm: use memweight()

Use memweight() to count the total number of bits set in memory area.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/md/dm-log.c

@@ -571,16 +571,6 @@ static void disk_dtr(struct dm_dirty_log *log)
 	destroy_log_context(lc);
 }
 
-static int count_bits32(uint32_t *addr, unsigned size)
-{
-	int count = 0, i;
-
-	for (i = 0; i < size; i++) {
-		count += hweight32(*(addr+i));
-	}
-	return count;
-}
-
 static void fail_log_device(struct log_c *lc)
 {
 	if (lc->log_dev_failed)
@@ -629,7 +619,8 @@ static int disk_resume(struct dm_dirty_log *log)
 
 	/* copy clean across to sync */
 	memcpy(lc->sync_bits, lc->clean_bits, size);
-	lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
+	lc->sync_count = memweight(lc->clean_bits,
+				lc->bitset_uint32_count * sizeof(uint32_t));
 	lc->sync_search = 0;
 
 	/* set the correct number of regions in the header */