Sync ethernet driver code with upstream Linux kernel:
-Reduce xmit_more code changes.
-Combine rx cleanup code into a function.
-Convert to build_skb.
-Improve rx loop by optimizing loop tracking.
https://lore.kernel.org/netdev/20210106144208.1935-1-liew.s.piaw@gmail.com/
Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
[Amend commit description, move patches to the top since they are going to be
upstreamed]
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>