telnetd: write LOGIN/DEAD_PROCESS utmp records. Closes bug 1363

function                                             old     new   delta
write_new_utmp                                         -     253    +253
skip_dev_pfx                                           -      30     +30
handle_sigchld                                        42      72     +30
telnetd_main                                        1650    1673     +23
make_new_session                                     415     438     +23
...
login_main                                          1140    1148      +8
update_utmp                                          337     313     -24
write_wtmp                                           220     154     -66
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 11/6 up/down: 406/-115)         Total: ~291 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/include/libbb.h b/include/libbb.h
index ea61701..f3121eb 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -797,9 +797,11 @@
 #endif
 
 #if ENABLE_FEATURE_UTMP
-void FAST_FUNC update_utmp(int new_type, const char *short_tty, const char *username, const char *opt_host);
+void FAST_FUNC write_new_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname);
+void FAST_FUNC update_utmp(pid_t pid, int new_type, const char *tty_name, const char *username, const char *hostname);
 #else
-# define update_utmp(new_type, short_tty, username, opt_host) ((void)0)
+# define write_new_utmp(pid, new_type, tty_name, username, hostname) ((void)0)
+# define update_utmp(pid, new_type, tty_name, username, hostname) ((void)0)
 #endif
 
 int execable_file(const char *name) FAST_FUNC;