net: mv643xx_eth: undo some opreations in mv643xx_eth_probe

Cannot directly return platform_get_irq return irq, there
are operations that need to be undone.

Fixes: bf2b8342 ("net: mv643xx_eth: use platform_get_irq() instead of platform_get_resource()")
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220316012444.2126070-1-chi.minghao@zte.com.cn


Signed-off-by: Jakub Kicinski <kuba@kernel.org>