f2fs: show current cp state

This patch shows whether checkpoint met any error case.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/debug.c

@@ -264,9 +264,10 @@ static int stat_show(struct seq_file *s, void *v)
 	list_for_each_entry(si, &f2fs_stat_list, stat_list) {
 		update_general_status(si->sbi);
 
-		seq_printf(s, "\n=====[ partition info(%pg). #%d, %s]=====\n",
+		seq_printf(s, "\n=====[ partition info(%pg). #%d, %s, CP: %s]=====\n",
 			si->sbi->sb->s_bdev, i++,
-			f2fs_readonly(si->sbi->sb) ? "RO": "RW");
+			f2fs_readonly(si->sbi->sb) ? "RO": "RW",
+			f2fs_cp_error(si->sbi) ? "Error": "Good");
 		seq_printf(s, "[SB: 1] [CP: 2] [SIT: %d] [NAT: %d] ",
 			   si->sit_area_segs, si->nat_area_segs);
 		seq_printf(s, "[SSA: %d] [MAIN: %d",