staging: ion: remove __GFP_NOWARN when use low order gfp flags

It's useful to show the current memory in detail when alloc failed.

And, there may be a lot of high order alloc failed, just show memory
when an order 0 alloc failed.
Signed-off-by: Chen Feng <puck.chen@hisilicon.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion_system_heap.c

@@ -30,7 +30,7 @@
 
 static gfp_t high_order_gfp_flags = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN |
 				     __GFP_NORETRY) & ~__GFP_RECLAIM;
-static gfp_t low_order_gfp_flags  = (GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN);
+static gfp_t low_order_gfp_flags  = (GFP_HIGHUSER | __GFP_ZERO);
 static const unsigned int orders[] = {8, 4, 0};
 
 static int order_to_index(unsigned int order)