[NET]: Eliminate unused argument from sk_stream_alloc_pskb

The 3rd argument is always zero (according to grep :) Eliminate
it and merge the function with sk_stream_alloc_skb.

This saves 44 more bytes, and together with the previous patch
we have:

add/remove: 1/0 grow/shrink: 0/8 up/down: 183/-751 (-568)
function                                     old     new   delta
sk_stream_alloc_skb                            -     183    +183
ip_rt_init                                   529     525      -4
arp_ignore                                   112     107      -5
__inet_lookup_listener                       284     274     -10
tcp_sendmsg                                 2583    2481    -102
tcp_sendpage                                1449    1300    -149
tso_fragment                                 417     258    -159
tcp_fragment                                1149     988    -161
__tcp_push_pending_frames                   1998    1837    -161

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sock.h b/include/net/sock.h
index 7d500a8..bcbf889 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1192,15 +1192,7 @@
 	}
 }
 
-struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
-		int size, int mem, gfp_t gfp);
-
-static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk,
-						  int size,
-						  gfp_t gfp)
-{
-	return sk_stream_alloc_pskb(sk, size, 0, gfp);
-}
+struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp);
 
 static inline struct page *sk_stream_alloc_page(struct sock *sk)
 {