net: mvneta: remove duplicate *_coal assignment

The style of the rx/tx queue's *_coal member assignment is:

static void foo_coal_set(...)
{
	set the coal in hw;
	update queue's foo_coal member; [1]
}

In other place, we call foo_coal_set(pp, queue->foo_coal), so the above [1]
is duplicated and could be removed.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: David S. Miller <davem@davemloft.net>