drivers/net/skfp/ess.c: fix compile warnings

  CC [M]  drivers/net/skfp/ess.o
drivers/net/skfp/ess.c: In function 'ess_send_response':
drivers/net/skfp/ess.c:513: warning: cast from pointer to integer of different size
drivers/net/skfp/ess.c: In function 'ess_send_alc_req':
drivers/net/skfp/ess.c:609: warning: cast from pointer to integer of different size
drivers/net/skfp/ess.c:639: warning: cast from pointer to integer of different size

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>