Fix BrcdFCSANlookupService to iterate multiple switches.

Changed close_connection to client.close_connection.
Fixed return map to key on fabric name instead of principal switch wwn.

Closes-Bug: 1303460
Change-Id: I3725c16cd416a028b85ac8ac6c0d895fd6900763
Merge "Fix BrcdFCSANlookupService to iterate multiple switches."