Should return a non-zero return code when deconfig does not find a target to deconfigure

https://github.com/open-power/eCMD/blob/1dd4a8467a09488613158a4b292f012a91617297/ecmd-core/cmd/ecmdMiscUser.C#L1039

Implement similar code in reconfig to say Unable to find a valid chip to execute command on and return a non-zero return code.