skbuff: fix compilation warnings in skb_dump()

The commit 6413139d ("skbuff: increase verbosity when dumping skb
data") introduced a few compilation warnings.

net/core/skbuff.c:766:32: warning: format specifies type 'unsigned
short' but the argument has type 'unsigned int' [-Wformat]
                       level, sk->sk_family, sk->sk_type,
sk->sk_protocol);
                                             ^~~~~~~~~~~
net/core/skbuff.c:766:45: warning: format specifies type 'unsigned
short' but the argument has type 'unsigned int' [-Wformat]
                       level, sk->sk_family, sk->sk_type,
sk->sk_protocol);
^~~~~~~~~~~~~~~

Fix them by using the proper types.

Fixes: 6413139d ("skbuff: increase verbosity when dumping skb data")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>