cx82310_eth: fix a memory leak bug

In cx82310_bind(), 'dev->partial_data' is allocated through kmalloc().
Then, the execution waits for the firmware to become ready. If the firmware
is not ready in time, the execution is terminated. However, the allocated
'dev->partial_data' is not deallocated on this path, leading to a memory
leak bug. To fix this issue, free 'dev->partial_data' before returning the
error.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>