[SCSI] libfc: use FC_MAX_ERROR_CNT

Though defined, FC_MAX_ERROR_CNT is not used. It is used now for CRC error in
the path of receiving FCP frame.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>