cmsis_dap: fix final byte for split transactions

When a transaction is split (due to having the final TMS bit high), the
value that is returned needs to be ORed into the final byte, rather than
simply overwriting it. This enables the full upper byte to be reported to
the caller.

Signed-off-by: Sean Cross <sean@xobs.io>

Author: xobs

src/platforms/hosted/dap_command.c

@@ -321,7 +321,7 @@ bool perform_dap_jtag_sequence(
 		memcpy(data_out, response + 1U, sequence_length);
 		/* And the final bit from the second response LSb */
 		if (sequences == 2U)
-			data_out[final_byte] = (response[1 + sequence_length] & 1U) << final_bit;
+			data_out[final_byte] |= (response[1 + sequence_length] & 1U) << final_bit;
 	}
 	/* And check that it succeeded */
 	return response[0] == DAP_RESPONSE_OK;