wlcore: fix pointer print out in wl1271_acx_set_rx_filter()

The debug print in wl1271_acx_set_rx_filter() was causing the
following warning:

  CC      drivers/net/wireless/ti/wlcore/acx.o
drivers/net/wireless/ti/wlcore/acx.c: In function ‘wl1271_acx_set_rx_filter’:
drivers/net/wireless/ti/wlcore/acx.c:1759:2: warning: cast from pointer to integer of different size

Instead of casting the pointer to an integer, use %p to print it our
instead.

Reported-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>