f2fs: rename f2fs_set/clear_bit to f2fs_test_and_set/clear_bit

Rename f2fs_set/clear_bit to f2fs_test_and_set/clear_bit, which mean
set/clear bit and return the old value, for better readability.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 6b08504..19de23b 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -648,10 +648,10 @@
 
 	/* Update valid block bitmap */
 	if (del > 0) {
-		if (f2fs_set_bit(offset, se->cur_valid_map))
+		if (f2fs_test_and_set_bit(offset, se->cur_valid_map))
 			f2fs_bug_on(sbi, 1);
 	} else {
-		if (!f2fs_clear_bit(offset, se->cur_valid_map))
+		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map))
 			f2fs_bug_on(sbi, 1);
 	}
 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))