staging: wilc1000: avoid NULL pointer dereference on error

The host_int_init() function can dereference the pstrWFIDrv pointer
while it is NULL on its error path. Jump directly to the _fail_ error
label in the end of the error handling path to avoid that.
	By doing that we also skip stopping our kthread and destroying
our message queue, but they were not started or created yet in that case
anyway.

This fixes the following coccinelle error:

  drivers/staging/wilc1000/host_interface.c:6100:17-33: ERROR: pstrWFIDrv is NULL but dereferenced.

Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Cc: Johnny Kim <johnny.kim@atmel.com>
Cc: Rachel Kim <rachel.kim@atmel.com>
Cc: Dean Lee <dean.lee@atmel.com>
Cc: Chris Park <chris.park@atmel.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>