Simplify, no need to reset signal disposition in handler

On modern systems, both *BSD and Linux using GLIBC/musl, the signal's
disposition is not reset to SIG_DFL on invocation of its handler.  On
Linux this is true because GLIBC/musl wraps signal() in sigaction()
with the same semantics as BSD.

A follow-up commit will refactor to use sigaction().

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/syslogd.c

@@ -2297,20 +2297,13 @@ void wallmsg(struct filed *f, struct iovec *iov)
 
 void reapchild(int signo)
 {
-	int saved_errno = errno;
-
-#ifdef linux
+	int saved_errno;
 	int status;
 
-	while (wait3(&status, WNOHANG, NULL) > 0)
+	saved_errno = errno;
+	while (waitpid(-1, &status, WNOHANG) > 0)
 		;
 
-	signal(SIGCHLD, reapchild); /* reset signal handler -ASP */
-#else
-	signal(SIGCHLD, reapchild); /* reset signal handler -ASP */
-	wait(NULL);
-#endif
-
 	errno = saved_errno;
 }
 
@@ -2415,7 +2408,6 @@ void domark(int signo)
 			DupesPending--;
 		}
 	}
-	(void)signal(SIGALRM, domark);
 
 	LastAlarm = MarkInterval - MarkSeq;
 	if (DupesPending && LastAlarm > TIMERINTVL)
@@ -3095,7 +3087,6 @@ static void logit(char *fmt, ...)
 void sighup_handler(int signo)
 {
 	restart = 1;
-	signal(SIGHUP, sighup_handler);
 }
 
 /**