genirq: Unexport nr_irqs

Unexport nr_irqs and declare it static now that all code that reads or
modifies nr_irqs has been converted to number_of_interrupts() /
set_number_of_interrupts(). Change the type of 'nr_irqs' from 'int' into
'unsigned int' to match the return type and argument type of the
irq_get_nr_iqs() / irq_set_nr_irqs() functions.

Signed-off-by: Bart Van Assche <[e-mail]>
Signed-off-by: Thomas Gleixner <[e-mail]>
Link: https://lore.kernel.org/all/[e-mail]

include/linux/irqnr.h

···
 #include <uapi/linux/irqnr.h>
 
 
-extern int nr_irqs;
 unsigned int irq_get_nr_irqs(void) __pure;
 unsigned int irq_set_nr_irqs(unsigned int nr);
 extern struct irq_desc *irq_to_desc(unsigned int irq);

kernel/irq/irqdesc.c

···
 	desc_smp_init(desc, node, affinity);
 }
 
-int nr_irqs = NR_IRQS;
-EXPORT_SYMBOL_GPL(nr_irqs);
+static unsigned int nr_irqs = NR_IRQS;
 
 /**
  * irq_get_nr_irqs() - Number of interrupts supported by the system.