be2net: Fixed a bug in be_cmd_get_regs().

Same WRB entry was being reused over different iterations of a
loop while issuing non-embedded IOCTL requests.Fixed couple of minor bugs
in this path as well.
Re-factored code to alloc/free memory for DMA outside of loop

Signed-off-by: Somnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>