net: qcom/emac: fix UAF in emac_remove

adpt is netdev private data and it cannot be
used after free_netdev() call. Using adpt after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() at the end of the
function.

Fixes: 54e19bc7

 ("net: qcom/emac: do not use devm on internal phy pdev")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>