Review radio metadata allocations/deallocations.

Bug: b/34054813
Test: VTS, manual
Change-Id: I1cbd7baf5b852cd3d4cab374eb67289f3938fff3
diff --git a/modules/radio/radio_hw.c b/modules/radio/radio_hw.c
index 150d173..54707d5 100644
--- a/modules/radio/radio_hw.c
+++ b/modules/radio/radio_hw.c
@@ -613,7 +613,12 @@
     metadata = info->metadata;
     *info = stub_tuner->program;
     info->metadata = metadata;
-    if (metadata != NULL && stub_tuner->program.metadata != NULL)
+    if (metadata == NULL) {
+        ALOGE("%s metadata is a nullptr", __func__);
+        status = -EINVAL;
+        goto exit;
+    }
+    if (stub_tuner->program.metadata != NULL)
         radio_metadata_add_metadata(&info->metadata, stub_tuner->program.metadata);
 
 exit: