scsi: qla2xxx: Set bit 15 for DIAG_ECHO_TEST MBC

commit 1d63496516c61e2e1351f10e6becbfc9ee511395 upstream.

Set bit (BIT_15) to send right ECHO payload information for Diagnostic
Echo Test command.

Signed-off-by: Joe Carnuccio <joe.carnuccio@cavium.com>
Signed-off-by: Himanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>