Fix `internal error: j_async: bad nzombie (0)' that occured with  `sudo pdksh -c "sleep 10&"'

Sudo sets RLIMIT_NPROC to unlimited, and sysconf returns that value as -1.
Index: pdksh-5.2.14/jobs.c
===================================================================
--- pdksh-5.2.14.orig/jobs.c	2008-05-26 21:46:41.000000000 +0200
+++ pdksh-5.2.14/jobs.c	2008-05-26 21:56:12.000000000 +0200
@@ -174,9 +174,9 @@
 static Job		*async_job;
 static pid_t		async_pid;
 
-static int		nzombie;	/* # of zombies owned by this process */
+static long		nzombie;	/* # of zombies owned by this process */
 static INT32		njobs;		/* # of jobs started */
-static int		child_max;	/* CHILD_MAX */
+static long		child_max;	/* CHILD_MAX */
 
 
 #ifdef JOB_SIGS
@@ -227,6 +227,12 @@
 	int mflagset;
 {
 	child_max = CHILD_MAX; /* so syscon() isn't always being called */
+#if defined(HAVE_SYSCONF) && defined(_SC_CHILD_MAX)
+	if (child_max < 0) {
+		child_max = LONG_MAX;
+	}
+#endif
+
 
 #ifdef JOB_SIGS
 	sigemptyset(&sm_default);
@@ -1131,7 +1137,7 @@
 		if (!oldest) {
 			/* XXX debugging */
 			if (!(async_job->flags & JF_ZOMBIE) || nzombie != 1) {
-				internal_errorf(0, "j_async: bad nzombie (%d)", nzombie);
+				internal_errorf(0, "j_async: bad nzombie (%ld)", nzombie);
 				nzombie = 0;
 			}
 			break;