ALSA: cs4236: fix error return comparison of an unsigned integer

ALSA: cs4236: fix error return comparison of an unsigned integer

The return from pnp_irq is an unsigned integer type resource_size_t
and hence the error check for a positive non-error code is always
going to be true.  A check for a non-failure return from pnp_irq
should in fact be for (resource_size_t)-1 rather than >= 0.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: 8b6f6eee30e4 ("[ALSA] Add CS4232 PnP BIOS support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20191122131354.58042-1-colin.king@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>