Revert "net: usb: ax88179_178a needs FLAG_SEND_ZLP"

Revert "net: usb: ax88179_178a needs FLAG_SEND_ZLP"

commit 91d7b3167eba63927a5d7b3b8f59fe14c5c61316 upstream.

This reverts commit 25855cda31d6def26952aebba6d4f96c285e9d62.

The usage of FLAG_SEND_ZLP causes problems to other firmware/hardware
versions that have no issues.

The FLAG_SEND_ZLP is not safe to use in this context.
See:
https://patchwork.ozlabs.org/project/netdev/patch/1270599787.8900.8.camel@Linuxdev4-laptop/#118378
The original problem needs another way to solve.

Fixes: 25855cda31d6 ("net: usb: ax88179_178a needs FLAG_SEND_ZLP")
Cc: stable@vger.kernel.org
Reported-by: Ronald Wahl <ronald.wahl@raritan.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216327
Link: https://bugs.archlinux.org/task/75491
Signed-off-by: Jose Alonso <joalonsof@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>