rtw88: signal completion even on firmware-request failure

Otherwise, the waiters (e.g., "modprobe rtwpci") will block forever.

Fixes: f530c196 ("rtw88: fix potential NULL pointer access for firmware")
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Acked-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/realtek/rtw88/main.c

@@ -1026,6 +1026,7 @@ static void rtw_load_firmware_cb(const struct firmware *firmware, void *context)
 
 	if (!firmware || !firmware->data) {
 		rtw_err(rtwdev, "failed to request firmware\n");
+		complete_all(&fw->completion);
 		return;
 	}