[SCSI] qla2xxx: Correct late-memset() of EFT buffer.

Original code would clear the buffer after the firmware had
already been initialized to use the buffer, thus potentially
and inadvertantly clearing data previously DMA'd by the
firmware.

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