Description of problem:
Specifying the udi with `rhcert-backend run --udi` does not test the requested device, and instead complains that the device could not be found

Version-Release number of selected component (if applicable):
redhat-certification-2.0-20151008.el7.noarch
redhat-certification-hardware-1.7.1-20150901.el7.noarch


How reproducible:
seems reliable

Steps to Reproduce:
1. plan rhcert tests
2. print rhcert test plan, note UDI listed for a device
3. attempt to test the device by udi

Actual results:
# rhcert-backend print | grep vide
hwcert/video                              /devices/pci0000:00/0000:00:02.0     

# rhcert-backend run --test=hwcert/video --udi=/devices/pci0000:00/0000:00:02.0
Verifying test plan
Warning: default plan called
Error: no tests match the supplied options


Expected results:
device tested

Additional info:

when udi is not specified running the same test:
                     
# rhcert-backend run --test=hwcert/video 
Verifying test plan
Warning: default plan called

Running the following tests:
video      udi=/devices/pci0000:00/0000:00:02.0 
info