qla3xxx: Remove unnecessary memset() in qla3xxx_send()

We do not need to zero out the 64 byte MAC request I/O control block.
  By zeroing out the control block and setting it to proper fields is
redundant work.  This is because in the qla3xxx_send() function we will
already set the proper fields in this structure.  The unused fields are
not looked at by the hardware and do not need to be zeroed out.

Signed-off-by: Benjamin Li <benjamin.li@qlogic.com>
Signed-off-by: Ron Mercer <ron.mercer@qlogic.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>