net: tap: check vlan with eth_type_vlan() method

mainline inclusion
from mainline-v5.12-rc1-dontuse
commit b69df260
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7IIRH
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b69df2608281b71575fbb3b9f426dbcc4be8a700



---------------------------

Replace some checks for ETH_P_8021Q and ETH_P_8021AD in
drivers/net/tap.c with eth_type_vlan.

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Link: https://lore.kernel.org/r/20210115023238.4681-1-dong.menglong@zte.com.cn


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Liu Jian <liujian56@huawei.com>

Conflicts:
	drivers/net/tap.c
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>