net: systemport: free dev before on error path

On the error path, it should goto the error handling label to free
allocated memory rather than directly return.

Fixes: 31bc72d9 ("net: systemport: fetch and use clock resources")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210120044423.1704-1-bianpan2016@163.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>