squashme: Add a comment

Author: ivmaykov

core/include/checks.h

@@ -37,6 +37,8 @@ int verify_conv_btc_to_satoshi(void);
  * Verifies that calling handle_incoming_message() with a serialized protobuf
  * message which exceeds nanopb field size limits (defined in proto .options
  * files) fails as expected.
+ *
+ * Note that as this function uses statically-allocated buffers, it is not thread-safe.
  */
 int verify_rpc_oversized_message_rejected(void);