Cast malloc result

Sources/CgRPC/shim/channel.c

@@ -49,7 +49,7 @@ cgrpc_channel *cgrpc_channel_create_secure(const char *address,
   channel_args.args = args;
   channel_args.num_args = num_args;
 
-  grpc_ssl_pem_key_cert_pair *client_credentials = malloc(sizeof (struct grpc_ssl_pem_key_cert_pair));
+  grpc_ssl_pem_key_cert_pair *client_credentials = (grpc_ssl_pem_key_cert_pair *) malloc(sizeof (struct grpc_ssl_pem_key_cert_pair));
   client_credentials->cert_chain = client_certs;
   client_credentials->private_key = client_private_key;
   if (client_certs == NULL || client_private_key == NULL) {