f2fs: fix inconsistent comments

Lack of maintenance on comments may mislead developers, fix them.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/gc.c

@@ -192,7 +192,10 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 		p->ofs_unit = sbi->segs_per_sec;
 	}
 
-	/* we need to check every dirty segments in the FG_GC case */
+	/*
+	 * adjust candidates range, should select all dirty segments for
+	 * foreground GC and urgent GC cases.
+	 */
 	if (gc_type != FG_GC &&
 			(sbi->gc_mode != GC_URGENT) &&
 			p->max_search > sbi->max_victim_search)