extcon: rt8973a: fix handling regmap_irq_get_virq result
extcon: rt8973a: fix handling regmap_irq_get_virq result

The function can return negative value.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/assign_signed_to_unsigned.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2046107

Signed-off-by: Andrzej Hajda <dcc2b772defa18622a340d324a717fd6b8ee2807@samsung.com>
Signed-off-by: Chanwoo Choi <42eed19c0f56a8d487deac90c6d19d6364b7ba73@samsung.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs