interconnect: Check for valid path in icc_set_bw()

Use IS_ERR() to ensure that the path passed to icc_set_bw() is valid.
Reviewed-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

drivers/interconnect/core.c

@@ -495,9 +495,12 @@ int icc_set_bw(struct icc_path *path, u32 avg_bw, u32 peak_bw)
 	size_t i;
 	int ret;
 
-	if (!path || !path->num_nodes)
+	if (!path)
 		return 0;
 
+	if (WARN_ON(IS_ERR(path) || !path->num_nodes))
+		return -EINVAL;
+
 	mutex_lock(&icc_lock);
 
 	old_avg = path->reqs[0].avg_bw;