f2fs: cleanup in f2fs_create_flush_cmd_control()

Just cleanup for readable, no functional changes.
Suggested-by: Chao Yu <chao@kernel.org>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/segment.c

@@ -620,12 +620,12 @@ int f2fs_create_flush_cmd_control(struct f2fs_sb_info *sbi)
 {
 	dev_t dev = sbi->sb->s_bdev->bd_dev;
 	struct flush_cmd_control *fcc;
-	int err = 0;
+	int err;
 
 	if (SM_I(sbi)->fcc_info) {
 		fcc = SM_I(sbi)->fcc_info;
 		if (fcc->f2fs_issue_flush)
-			return err;
+			return 0;
 		goto init_thread;
 	}
 
@@ -638,7 +638,7 @@ int f2fs_create_flush_cmd_control(struct f2fs_sb_info *sbi)
 	init_llist_head(&fcc->issue_list);
 	SM_I(sbi)->fcc_info = fcc;
 	if (!test_opt(sbi, FLUSH_MERGE))
-		return err;
+		return 0;
 
 init_thread:
 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
@@ -650,7 +650,7 @@ int f2fs_create_flush_cmd_control(struct f2fs_sb_info *sbi)
 		return err;
 	}
 
-	return err;
+	return 0;
 }
 
 void f2fs_destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)