print errors on stderr;

--- a/Admin/exec_process/exec_process.c	Fri Apr 27 19:50:32 2012 +0200
+++ b/Admin/exec_process/exec_process.c	Fri Apr 27 19:54:05 2012 +0200
@@ -11,7 +11,7 @@
 
 static void fail(const char *msg)
 {
-  printf("%s\n", msg);
+  fprintf(stderr, "%s\n", msg);
   exit(2);
 }
 
@@ -21,7 +21,7 @@
   /* args */
 
   if (argc != 3) {
-    printf("Bad arguments\n");
+    fprintf(stderr, "Bad arguments\n");
     exit(1);
   }
   char *pid_name = argv[1];