mwifiex: consolidate mwifiex_sdio_probe() error paths

Instead of duplicating part of the cleanups needed in case of an error
in .probe callback, have a single error path and use goto labels as is
common practice in the kernel.

This also has the nice side effect that the cleanup operations are made
in the inverse order of their counterparts, which was not the case for
the mwifiex_add_card() error path.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>