net: hinic: Fix error handling in hinic_module_init()

A problem about hinic create debugfs failed is triggered with the
following log given:

[ 931.419023] debugfs: Directory 'hinic' with parent '/' already present!

The reason is that hinic_module_init() returns pci_register_driver()
directly without checking its return value, if pci_register_driver()
failed, it returns without destroy the newly created debugfs, resulting
the debugfs of hinic can never be created later.

hinic_module_init()
hinic_dbg_register_debugfs() # create debugfs directory
pci_register_driver()
driver_register()
bus_add_driver()
priv = kzalloc(...) # OOM happened
# return without destroy debugfs directory

Fix by removing debugfs when pci_register_driver() returns error.

Fixes: 253ac3a97921 ("hinic: add support to query sq info")
Signed-off-by: Yuan Can <[e-mail]>
Reviewed-by: Leon Romanovsky <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/ethernet/huawei/hinic/hinic_main.c

···
 
 static int __init hinic_module_init(void)
 {
+	int ret;
+
 	hinic_dbg_register_debugfs(HINIC_DRV_NAME);
-	return pci_register_driver(&hinic_driver);
+
+	ret = pci_register_driver(&hinic_driver);
+	if (ret)
+		hinic_dbg_unregister_debugfs();
+
+	return ret;
 }
 
 static void __exit hinic_module_exit(void)