[PATCH] ppc64: hugepage bugfix

Fix a stupid unbalanced lock bug in the ppc64 hugepage code.  Lead
rapidly to a crash if both CONFIG_HUGETLB_PAGE and CONFIG_PREEMPT were
enabled (even without actually using hugepages at all).
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ppc64/mm/hugetlbpage.c

@@ -745,7 +745,7 @@ void hugetlb_mm_free_pgd(struct mm_struct *mm)
 
 	pgdir = mm->context.huge_pgdir;
 	if (! pgdir)
-		return;
+		goto out;
 
 	mm->context.huge_pgdir = NULL;
 
@@ -768,6 +768,7 @@ void hugetlb_mm_free_pgd(struct mm_struct *mm)
 	BUG_ON(memcmp(pgdir, empty_zero_page, PAGE_SIZE));
 	kmem_cache_free(zero_cache, pgdir);
 
+ out:
 	spin_unlock(&mm->page_table_lock);
 }