CT Ping and ELS cmds fail for NVMe targets.  Check if port is online before
sending ELS instead of sending login.

Cc: stable@vger.kernel.org
Signed-off-by: Shreyas Deodhar <sdeodhar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>