php: destroy grpc_byte_buffer after startBatch

src/php/ext/grpc/byte_buffer.c

@@ -72,6 +72,7 @@ void byte_buffer_to_string(grpc_byte_buffer *buffer, char **out_string,
   while (grpc_byte_buffer_reader_next(&reader, &next) != 0) {
     memcpy(string + offset, GPR_SLICE_START_PTR(next), GPR_SLICE_LENGTH(next));
     offset += GPR_SLICE_LENGTH(next);
+    gpr_slice_unref(next);
   }
   *out_string = string;
   *out_length = length;

src/php/ext/grpc/call.c

@@ -492,6 +492,14 @@ cleanup:
   if (status_details != NULL) {
     gpr_free(status_details);
   }
+  for (int i = 0; i < op_num; i++) {
+    if (ops[i].op == GRPC_OP_SEND_MESSAGE) {
+      grpc_byte_buffer_destroy(ops[i].data.send_message);
+    }
+    if (ops[i].op == GRPC_OP_RECV_MESSAGE) {
+      grpc_byte_buffer_destroy(message);
+    }
+  }
   RETURN_DESTROY_ZVAL(result);
 }