usb: gadget: udc: s3c2410: add IRQ check

usb: gadget: udc: s3c2410: 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_irq() (which takes
*unsigned* IRQ #), causing it to fail with -EINVAL, overriding an original
error code. Stop calling request_irq() with the invalid IRQ #s.

Fixes: 188db4435ac6 ("usb: gadget: s3c: use platform resources")
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/bd69b22c-b484-5a1f-c798-78d4b78405f2@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>