livepatch: Fix missing unlock on error in klp_enable_patch()

Add missing unlock when try_module_get() fails in klp_enable_patch().

Fixes: 5ef3dd2 ("livepatch: Fix kobject refcount bug on klp_init_patch_early failure path")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
Acked-by: David Vernet <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: Yang Yingliang

kernel/livepatch/core.c

@@ -1047,8 +1047,10 @@ int klp_enable_patch(struct klp_patch *patch)
 		return -EINVAL;
 	}
 
-	if (!try_module_get(patch->mod))
+	if (!try_module_get(patch->mod)) {
+		mutex_unlock(&klp_mutex);
 		return -ENODEV;
+	}
 
 	klp_init_patch_early(patch);