[IA64] don't double >> PAGE_SHIFT pointer for /dev/kmem access

Don't PAGE_SHIFT pointer before handing it to virt_to_page() in
xlate_dev_kmem_ptr() as it results in a double shift.

Spotted by Bob Montgomery.
Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

include/asm-ia64/uaccess.h

@@ -389,7 +389,7 @@ xlate_dev_kmem_ptr (char * p)
 	struct page *page;
 	char * ptr;
 
-	page = virt_to_page((unsigned long)p >> PAGE_SHIFT);
+	page = virt_to_page((unsigned long)p);
 	if (PageUncached(page))
 		ptr = (char *)__pa(p) + __IA64_UNCACHED_OFFSET;
 	else