net: dsa: Fix a typo in tag_rtl4_a.c

Modify "Apparantly" to "Apparently" in net/dsa/tag_rtl4_a.c..

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Lu Wei <luwei32@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>