CiscoFCSanLookupService passing command as string

The command to fetch the fcns database was passed
as a string in the class CiscoFCSanLookupService
(FCSanLookupService).  I has to be passed as list.

Updated the test_cisco_fc_san_lookup_service.py file
with the unit test for this change.

Closes-Bug: 1385980
Change-Id: Ia35662190047450d054b1831aa1c530ca4656101
Merge "CiscoFCSanLookupService passing command as string"