sparc: Fix minor SPARC32 compile error

When CONFIG_PROC_FS is unset, include/linux/interrupt.h defines
init_irq_proc() as an empty function.

arch/sparc/kernel/irq_32.c defines this function unconditionally.

Fix the latter so that it only defines this function when CONFIG_PROC_FS
is set.

This fixes the following error:
arch/sparc/kernel/irq_32.c:672: error: redefinition of 'init_irq_proc'
include/linux/interrupt.h:461: error: previous definition of
'init_irq_proc' was here

This was found using randconfig builds.
Signed-off-by: NJulian Calaby <julian.calaby@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/kernel/irq_32.c

@@ -669,7 +669,9 @@ void __init init_IRQ(void)
 	btfixup();
 }
 
+#ifdef CONFIG_PROC_FS
 void init_irq_proc(void)
 {
 	/* For now, nothing... */
 }
+#endif /* CONFIG_PROC_FS */