sparc64: Fix gfp_flags setting in tsb_grow().

We should "|= more_flags" rather than "= more_flags".
Reported-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/mm/tsb.c

@@ -314,7 +314,7 @@ void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
 retry_tsb_alloc:
 	gfp_flags = GFP_KERNEL;
 	if (new_size > (PAGE_SIZE * 2))
-		gfp_flags = __GFP_NOWARN | __GFP_NORETRY;
+		gfp_flags |= __GFP_NOWARN | __GFP_NORETRY;
 
 	new_tsb = kmem_cache_alloc_node(tsb_caches[new_cache_index],
 					gfp_flags, numa_node_id());