some little fix

Makefile.in

@@ -634,7 +634,6 @@ clean::
 
 install_no_local::
 	cp -f bin/why3-cpulimit $(BINDIR)
-	cp -f bin/why3-cpulimit_time $(BINDIR)
 
 ########
 # bench

src/tools/cpulimit.c

@@ -45,7 +45,7 @@ int main(int argc, char *argv[]) {
     fprintf(stderr, "usage: %s <time limit in seconds> \
 <virtual memory limit in MiB> <print time yes|no> <command>\n\
 a null value sets no limit (keeps the actual limit)\n", argv[0]);
-    return 1;
+    return EXIT_FAILURE;
   }
 
   /* Fork if requested */