platform_get_irq() returns an error code, but the sata_rcar driver
ignores it and always returns -EINVAL. This is not correct, and
prevents -EPROBE_DEFER from being propagated properly. Also,
notice that platform_get_irq() no longer returns 0 on error.
Print error message and propagate the return value of platform_get_irq
on failure.
Cc: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>