staging: wilc1000: remove goto from linux_wlan_firmware_download

This patch remove goto feature from linux_wlan_firmware_download function.
Goto feature is return result.
So, remove goto functions and it was replaced with the return value directly.

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>