net: Update kernel-doc for __alloc_skb()

__alloc_skb() now extends tailroom to allow the use of padding added
by the heap allocator.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 016694d..1d74cea 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -160,8 +160,8 @@
  *	@node: numa node to allocate memory on
  *
  *	Allocate a new &sk_buff. The returned buffer has no headroom and a
- *	tail room of size bytes. The object has a reference count of one.
- *	The return is the buffer. On a failure the return is %NULL.
+ *	tail room of at least size bytes. The object has a reference count
+ *	of one. The return is the buffer. On a failure the return is %NULL.
  *
  *	Buffers may only be allocated from interrupts using a @gfp_mask of
  *	%GFP_ATOMIC.