[openwrt/openwrt] realtek: cleanup debugfs creation in serdes driver

[LEDE Commits]

robimarko pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/3c073b5cb208e9ca77a786f38dc941316ee25c67

commit 3c073b5cb208e9ca77a786f38dc941316ee25c67
Author: Markus Stockhausen <markus.stockhausen at gmx.de>
AuthorDate: Sun Dec 14 10:03:47 2025 +0100

    realtek: cleanup debugfs creation in serdes driver
    
    debugfs_create_dir() has a proper logic to handle existing directories.
    Skip the manual test. Additionally quit early if directory creation fails.
    
    Signed-off-by: Markus Stockhausen <markus.stockhausen at gmx.de>
    Link: https://github.com/openwrt/openwrt/pull/21157
    Signed-off-by: Robert Marko <robimarko at gmail.com>
---
 .../realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto-serdes.c  | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto-serdes.c b/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto-serdes.c
index 2bd38f382d..394af71250 100644
--- a/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto-serdes.c
+++ b/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto-serdes.c
@@ -155,9 +155,9 @@ static int rtsds_debug_init(struct rtsds_ctrl *ctrl, u32 sds)
 	dbg_info->ctrl = ctrl;
 	dbg_info->sds = sds;
 
-	root = debugfs_lookup(RTSDS_DBG_ROOT_DIR, NULL);
-	if (!root)
-		root = debugfs_create_dir(RTSDS_DBG_ROOT_DIR, NULL);
+	root = debugfs_create_dir(RTSDS_DBG_ROOT_DIR, NULL);
+	if (IS_ERR(root))
+		return PTR_ERR(root);
 
 	snprintf(dirname, sizeof(dirname), "serdes.%d", sds);
 	dir = debugfs_create_dir(dirname, root);