f2fs: optimize the init_dirty_segmap function

Optimize the while loop condition

Since this condition will always be true and while loop will
be terminated by the following condition in code:

if (segno >= TOTAL_SEGS(sbi))
    break;
Hence we can replace the while loop condition with while(1)
instead of always checking for segno to be less than Total segs.

Also we do not need to use TOTAL_SEGS() everytime. We can store
this value in a local variable since this value is constant.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NPankaj Kumar <pankaj.km@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/segment.c

@@ -1582,13 +1582,13 @@ static void init_dirty_segmap(struct f2fs_sb_info *sbi)
 {
 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 	struct free_segmap_info *free_i = FREE_I(sbi);
-	unsigned int segno = 0, offset = 0;
+	unsigned int segno = 0, offset = 0, total_segs = TOTAL_SEGS(sbi);
 	unsigned short valid_blocks;
 
-	while (segno < TOTAL_SEGS(sbi)) {
+	while (1) {
 		/* find dirty segment based on free segmap */
-		segno = find_next_inuse(free_i, TOTAL_SEGS(sbi), offset);
-		if (segno >= TOTAL_SEGS(sbi))
+		segno = find_next_inuse(free_i, total_segs, offset);
+		if (segno >= total_segs)
 			break;
 		offset = segno + 1;
 		valid_blocks = get_valid_blocks(sbi, segno, 0);