be2net: Refactored be_cmds.c file.

Moved the .sge. field's population inside be_cmd_hdr_prepare.
Populating wrb->tag0 and tag1 inside be_cmd_hdr_prepare
Signed-off-by: NSomnath Kotur <somnath.kotur@emulex.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>