Remove the empty resource name workaround in nidcpower self_cal system test

[sbethur]

Description of issue

Due to a bug in NI-DCPower driver runtime 2022 Q3 (Internal error AB#1973297), doing self_cal on a simulated session with a resource name that doesn't match real h/w present in the system returns an error.

To work around this bug, the self_cal system test passes an empty string for resource_name. Once the internal bug is fixed, the workaround should be removed.