staging: wilc1000: removes goto definitions from wilc_wlan_firmware_download

This patch removes goto definitions from wilc_wlan_firmware_download function.
Goto '_fail_1' feature is error return.
It returns error type directly without result variable replacement as well.

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