scsi: scsi_transport_fc: Fix FPIN Link Integrity statistics counters

In the original FPIN commit, stats were incremented by the event_count.
Event_count is the minimum # of events that must occur before an FPIN is
sent. Thus, its not the actual number of events, and could be significantly
off (too low) as it doesn't reflect anything not reported.  Rather than
attempt to count events, have the statistic count how many FPINS cross the
threshold and were reported.

Link: https://lore.kernel.org/r/20220301175536.60250-1-jsmart2021@gmail.com
Fixes: 3dcfe0de

 ("scsi: fc: Parse FPIN packets and update statistics")
Cc: <stable@vger.kernel.org> # v5.11+
Cc: Shyam Sundar <ssundar@marvell.com>
Cc: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>