Remove alloc in packet forwarding path. (#3305)

* Remove alloc in packet forwarding path.

Unlikely logger creation was doing allocs. Replace it with a function
like in rtpstats_receiver.go so that allocations do not happen
unnecessarily.

* variable rename

* one more place

pkg/sfu/buffer/buffer_test.go

@@ -322,5 +322,4 @@ func BenchmarkMemcpu(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		copy(buf2, buf)
 	}
-
 }