staging: qlge: refine variable name

tmp as a variable name don't have much information, change tmp to dma.

Signed-off-by: Binyi Han <dantengknight@gmail.com>
Link: https://lore.kernel.org/r/20220715061754.GA6657@cloud-MacBookPro


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>