net: stmmac: remove redundant continue statement

commit c44924c5 upstream.

The continue statement in the for-loop has no effect, remove it.

Addresses-Coverity: ("Continue has no effect")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Yongxin Liu <yongxin.liu@windriver.com>