[SCSI] qla2xxx: Correct usage of inconsistent timeout values while issuing ELS commands.

The original code would incorrectly hardcode ELS timeout values
rather than using the traditional '2 * r_a_tov' value.  In some
cases, the hardcoded values would be larger than the
mailbox-command-timeout and result in a needless BIG_HAMMER (ISP
reset), the typical recovery mechanism employed in such cases.

The second defect in the original code was in the assignment of
the default 'ha->r_a_tov' to twice the traditional value.
Correct this by setting the value to 10 seconds.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>