net: kalmia: fix memory leaks

In kalmia_init_and_get_ethernet_addr(), 'usb_buf' is allocated through
kmalloc(). In the following execution, if the 'status' returned by
kalmia_send_init_packet() is not 0, 'usb_buf' is not deallocated, leading
to memory leaks. To fix this issue, add the 'out' label to free 'usb_buf'.

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