sctp: try harder to figure out address family when checking wildcards

sctp_is_any() function that is used to check for wildcard addresses
only looks at the address itself to determine the address family.
This function is used in the API to check the address passed in from
the user.  If the user simply zerroes out the sockaddr_storage and
pass that in, we'll end up failing.  So, let's try harder to determine
the address family by also checking the socket if it's possible.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 0dc1b72..94c62e4 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -1228,7 +1228,7 @@
 
 sctp_scope_t sctp_scope(const union sctp_addr *);
 int sctp_in_scope(const union sctp_addr *addr, const sctp_scope_t scope);
-int sctp_is_any(const union sctp_addr *addr);
+int sctp_is_any(struct sock *sk, const union sctp_addr *addr);
 int sctp_addr_is_valid(const union sctp_addr *addr);