Include priv.h for priv_set_t.

From alex at cooperi.net.

openbsd-compat/port-solaris.h

@@ -27,6 +27,7 @@ void solaris_contract_post_fork_child(void);
 void solaris_contract_post_fork_parent(pid_t pid);
 void solaris_set_default_project(struct passwd *);
 # ifdef USE_SOLARIS_PRIVS
+#include <priv.h>
 priv_set_t *solaris_basic_privset(void);
 void solaris_drop_privs_pinfo_net_fork_exec(void);
 void solaris_drop_privs_root_pinfo_net(void);