usb: phy: tahvo: add IRQ check

usb: phy: tahvo: add IRQ check

The driver neglects to check the result of platform_get_irq()'s call and
blithely passes the negative error codes to request_threaded_irq() (which
takes *unsigned* IRQ #), causing it to fail with -EINVAL, overriding an
original error code.  Stop calling request_threaded_irq() with the invalid
IRQ #s.

Fixes: 9ba96ae5074c ("usb: omap1: Tahvo USB transceiver driver")
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/8280d6a4-8e9a-7cfe-1aa9-db586dc9afdf@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>