[IA64] re-enable preempt before page allocation for pgtable quicklist

This is a fix to the pgtable_quicklist code.  There is a GFP_KERNEL
allocation in pgtable_quicklist_alloc(), which spews the usual warnings
if the kernel is under heavy VM pressure and the reclaim code is
invoked.  re-enable preempt before we allocate the new page.

This patch is against 2.6.12-rc2-mm2

Signed-off-by:  Martin Hicks <mort@sgi.com>
Signed-off-by:  Tony Luck <tony.luckintel.com>

include/asm-ia64/pgalloc.h

@@ -49,12 +49,12 @@ static inline void *pgtable_quicklist_alloc(void)
 		pgtable_quicklist = (unsigned long *)(*ret);
 		ret[0] = 0;
 		--pgtable_quicklist_size;
+		preempt_enable();
 	} else {
+		preempt_enable();
 		ret = (unsigned long *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
 	}
 
-	preempt_enable();
-
 	return ret;
 }