livepatch: __klp_disable_patch() should never be called for disabled patches

__klp_disable_patch() should never be called when the patch is not
enabled. Let's add the same warning that we have in __klp_enable_patch().

This allows to remove the check when calling klp_pre_unpatch_callback().
It was strange anyway because it repeatedly checked per-patch flag
for each patched object.

Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

kernel/livepatch/core.c

@@ -282,6 +282,9 @@ static int __klp_disable_patch(struct klp_patch *patch)
 {
 	struct klp_object *obj;
 
+	if (WARN_ON(!patch->enabled))
+		return -EINVAL;
+
 	if (klp_transition_patch)
 		return -EBUSY;
 
@@ -293,7 +296,7 @@ static int __klp_disable_patch(struct klp_patch *patch)
 	klp_init_transition(patch, KLP_UNPATCHED);
 
 	klp_for_each_object(patch, obj)
-		if (patch->enabled && obj->patched)
+		if (obj->patched)
 			klp_pre_unpatch_callback(obj);
 
 	/*