staging: slicoss: fix use-after-free in slic_entry_probe

This patch fixes a use-after-free bug that can cause a kernel
oops. If slic_card_init fails then slic_entry_probe (the pci
probe() function for this device) will return error without
cleaning up memory.

Signed-off-by: David Matlack <dmatlack@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>