scsi: libfc: free skb when receiving invalid flogi resp

The issue to be fixed in this commit is when libfc found it received a
invalid FLOGI response from FC switch, it would return without freeing the
fc frame, which is just the skb data. This would cause memory leak if FC
switch keeps sending invalid FLOGI responses.

This fix is just to make it execute `fc_frame_free(fp)` before returning
from function `fc_lport_flogi_resp`.

Signed-off-by: Ming Lu <ming.lu@citrix.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>