soc: fsl: qe: fix static checker warning

The patch be7ecbd240b2: "soc: fsl: qe: convert QE interrupt
controller to platform_device" from Aug 3, 2021, leads to the
following static checker warning:

drivers/soc/fsl/qe/qe_ic.c:438 qe_ic_init()
warn: unsigned 'qe_ic->virq_low' is never less than zero.

In old variant irq_of_parse_and_map() returns zero if failed so
unsigned int for virq_high/virq_low was ok.
In new variant platform_get_irq() returns negative error codes
if failed so we need to use int for virq_high/virq_low.

Also simplify high_handler checking and remove the curly braces
to make checkpatch happy.

Fixes: be7ecbd240b2 ("soc: fsl: qe: convert QE interrupt controller to platform_device")
Signed-off-by: Maxim Kochetkov <[e-mail]>
Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Li Yang <[e-mail]>

drivers/soc/fsl/qe/qe_ic.c

···
 	struct irq_chip hc_irq;
 
 	/* VIRQ numbers of QE high/low irqs */
-	unsigned int virq_high;
-	unsigned int virq_low;
+	int virq_high;
+	int virq_low;
 };
 
 /*
···
 	qe_ic->virq_high = platform_get_irq(pdev, 0);
 	qe_ic->virq_low = platform_get_irq(pdev, 1);
 
-	if (qe_ic->virq_low < 0) {
+	if (qe_ic->virq_low <= 0)
 		return -ENODEV;
-	}
 
-	if (qe_ic->virq_high != qe_ic->virq_low) {
+	if (qe_ic->virq_high > 0 && qe_ic->virq_high != qe_ic->virq_low) {
 		low_handler = qe_ic_cascade_low;
 		high_handler = qe_ic_cascade_high;
 	} else {
···
 	irq_set_handler_data(qe_ic->virq_low, qe_ic);
 	irq_set_chained_handler(qe_ic->virq_low, low_handler);
 
-	if (qe_ic->virq_high && qe_ic->virq_high != qe_ic->virq_low) {
+	if (high_handler) {
 		irq_set_handler_data(qe_ic->virq_high, qe_ic);
 		irq_set_chained_handler(qe_ic->virq_high, high_handler);
 	}