scsi: bnx2fc: Return failure if io_req is already in ABTS processing

Return failure from bnx2fc_eh_abort() if io_req is already in ABTS
processing.

Link: https://lore.kernel.org/r/20210519061416.19321-1-jhasan@marvell.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Javed Hasan <jhasan@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>