rtlwifi: rtl8821ae: fix firmware is not ready to run

Without this patch, firmware will not run properly on rtl8821ae, and it
causes bad user experience. For example, bad connection performance with
low rate, higher power consumption, and so on.

rtl8821ae uses two kinds of firmwares for normal and WoWlan cases, and
each firmware has firmware data buffer and size individually. Original
code always overwrite size of normal firmware rtlpriv->rtlhal.fwsize, and
this mismatch causes firmware checksum error, then firmware can't start.

In this situation, driver gives message "Firmware is not ready to run!".

Fixes: fe89707f ("rtlwifi: rtl8821ae: Simplify loading of WOWLAN firmware")
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Cc: Stable <stable@vger.kernel.org> # 4.0+
Reviewed-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>