m68k/page_no.h: force __va argument to be unsigned long

Add explicit casting to unsigned long to the __va() parameter
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/page_no.h

@@ -18,7 +18,7 @@ extern unsigned long memory_end;
 #define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE
 
 #define __pa(vaddr)		((unsigned long)(vaddr))
-#define __va(paddr)		((void *)(paddr))
+#define __va(paddr)		((void *)((unsigned long)(paddr)))
 
 #define virt_to_pfn(kaddr)	(__pa(kaddr) >> PAGE_SHIFT)
 #define pfn_to_virt(pfn)	__va((pfn) << PAGE_SHIFT)