wifi: rtlwifi: do not complete firmware loading needlessly

The only code waiting for completion is driver removal, which will not be
called when probe returns a failure. So this completion is unnecessary.

Fixes: b0302aba ("rtlwifi: Convert to asynchronous firmware load")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com>
Acked-by: Ping-Ke Shih <pkshih@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
Link: https://patch.msgid.link/20241107133322.855112-2-cascardo@igalia.com