bpf: Remove redundant __GFP_NOWARN

Commit 16f5dfb ("gfp: include __GFP_NOWARN in GFP_NOWAIT")
made GFP_NOWAIT implicitly include __GFP_NOWARN.

Therefore, explicit __GFP_NOWARN combined with GFP_NOWAIT
(e.g., `GFP_NOWAIT | __GFP_NOWARN`) is now redundant. Let's clean
up these redundant flags across subsystems.

No functional changes.

Signed-off-by: Qianfeng Rong <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: qianfengrong

kernel/bpf/devmap.c

@@ -865,7 +865,7 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net,
 	struct bpf_dtab_netdev *dev;
 
 	dev = bpf_map_kmalloc_node(&dtab->map, sizeof(*dev),
-				   GFP_NOWAIT | __GFP_NOWARN,
+				   GFP_NOWAIT,
 				   dtab->map.numa_node);
 	if (!dev)
 		return ERR_PTR(-ENOMEM);

kernel/bpf/local_storage.c

@@ -165,7 +165,7 @@ static long cgroup_storage_update_elem(struct bpf_map *map, void *key,
 	}
 
 	new = bpf_map_kmalloc_node(map, struct_size(new, data, map->value_size),
-				   __GFP_ZERO | GFP_NOWAIT | __GFP_NOWARN,
+				   __GFP_ZERO | GFP_NOWAIT,
 				   map->numa_node);
 	if (!new)
 		return -ENOMEM;