staging: wilc1000: fix a couple of memory leaks

The ENOMEM error return paths are not free'ing allocated memory
resulting in a memory leak of allocated structures. Perform the
required kfree to fix the memory leaks.

Issue discovered with static analysis using CoverityScan

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>