ocfs2: correctly use ocfs2_find_next_zero_bit()

If no bits are zero, ocfs2_find_next_zero_bit() will return max size, so
check the return value with -1 is meaningless. Correct this usage and
cleanup the code.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Joseph Qi <[e-mail]>
Reviewed-by: Heming Zhao <[e-mail]>
Cc: Mark Fasheh <[e-mail]>
Cc: Joel Becker <[e-mail]>
Cc: Junxiao Bi <[e-mail]>
Cc: Changwei Ge <[e-mail]>
Cc: Gang He <[e-mail]>
Cc: Jun Piao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

fs/ocfs2/localalloc.c

···
 
 	numfound = bitoff = startoff = 0;
 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
-	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) != -1) {
-		if (bitoff == left) {
-			/* mlog(0, "bitoff (%d) == left", bitoff); */
-			break;
-		}
-		/* mlog(0, "Found a zero: bitoff = %d, startoff = %d, "
-		   "numfound = %d\n", bitoff, startoff, numfound);*/
-
+	while ((bitoff = ocfs2_find_next_zero_bit(bitmap, left, startoff)) <
+	       left) {
 		/* Ok, we found a zero bit... is it contig. or do we
 		 * start over?*/
 		if (bitoff == startoff) {
···
 	start = count = 0;
 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
 
-	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))
-	       != -1) {
-		if ((bit_off < left) && (bit_off == start)) {
+	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start)) <
+	       left) {
+		if (bit_off == start) {
 			count++;
 			start++;
 			continue;
···
 				goto bail;
 			}
 		}
-		if (bit_off >= left)
-			break;
+
 		count = 1;
 		start = bit_off + 1;
 	}

fs/ocfs2/reservations.c

···
 
 	start = search_start;
 	while ((offset = ocfs2_find_next_zero_bit(bitmap, resmap->m_bitmap_len,
-						 start)) != -1) {
+					start)) < resmap->m_bitmap_len) {
 		/* Search reached end of the region */
 		if (offset >= (search_start + search_len))
 			break;

fs/ocfs2/suballoc.c

···
 	found = start = best_offset = best_size = 0;
 	bitmap = bg->bg_bitmap;
 
-	while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
-		if (offset == total_bits)
-			break;
-
+	while ((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) <
+	       total_bits) {
 		if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
 			/* We found a zero, but we can't use it as it
 			 * hasn't been put to disk yet! */