interconnect: core: fix error return code of icc_link_destroy()

When krealloc() fails and new is NULL, no error return code of
icc_link_destroy() is assigned.
To fix this bug, ret is assigned with -ENOMEM hen new is NULL.
Reported-by: NTOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: NJia-Ju Bai <baijiaju1990@gmail.com>
Link: https://lore.kernel.org/r/20210306132857.17020-1-baijiaju1990@gmail.comSigned-off-by: NGeorgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/core.c

@@ -942,6 +942,8 @@ int icc_link_destroy(struct icc_node *src, struct icc_node *dst)
 		       GFP_KERNEL);
 	if (new)
 		src->links = new;
+	else
+		ret = -ENOMEM;
 
 out:
 	mutex_unlock(&icc_lock);