staging: wilc1000: rename pIP_Add_buff of function dev_state_ev_handler

This patch renames pIP_Add_buff of function dev_state_ev_handler to ip_addr_buf
to avoid CamelCase naming convention.

Signed-off-by: Leo Kim <leo.kim@atmel.com>
Signed-off-by: Glen Lee <glen.lee@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>