char: misc: deallocate static minor in error path

commit 6d991f5 upstream.

When creating sysfs files fail, the allocated minor must be freed such that
it can be later reused. That is specially harmful for static minor numbers,
since those would always fail to register later on.

Fixes: 6d04d2b ("misc: misc_minor_alloc to use ida for all dynamic/misc dynamic minors")
Cc: stable <stable@kernel.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Link: https://lore.kernel.org/r/20250123123249.4081674-5-cascardo@igalia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Thadeu Lima de Souza Cascardo

drivers/char/misc.c

@@ -264,8 +264,8 @@ int misc_register(struct miscdevice *misc)
 		device_create_with_groups(&misc_class, misc->parent, dev,
 					  misc, misc->groups, "%s", misc->name);
 	if (IS_ERR(misc->this_device)) {
+		misc_minor_free(misc->minor);
 		if (is_dynamic) {
-			misc_minor_free(misc->minor);
 			misc->minor = MISC_DYNAMIC_MINOR;
 		}
 		err = PTR_ERR(misc->this_device);