Input: ep93xx_keypad - fix handling of platform_get_irq() error

platform_get_irq() returns -ERRNO on error.  In such case comparison
to 0 would pass the check.

Fixes: 60214f05 ("Input: ep93xx_keypad - update driver to new core support")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200828145744.3636-1-krzk@kernel.orgSigned-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/ep93xx_keypad.c

@@ -250,8 +250,8 @@ static int ep93xx_keypad_probe(struct platform_device *pdev)
 	}
 
 	keypad->irq = platform_get_irq(pdev, 0);
-	if (!keypad->irq) {
-		err = -ENXIO;
+	if (keypad->irq < 0) {
+		err = keypad->irq;
 		goto failed_free;
 	}