Show "swap failed" instead of "swap completed" in case transaction failed

[amytsang]

an example here the swap failed with "slippage error" while UI shows as "swap completed"

hash of the failed tx https://etherscan.io/tx/0xabaa75582b2111f60e31381cabb825a2c3c78f2ffbe1dbd93ea36be491e9004f