Make sure we close all open files.

sysdeps/linux/glibtop_server.h

@@ -69,10 +69,11 @@ proc_file_to_buffer (char *buffer, const char *fmt, pid_t pid)
 	if (fd < 0) return -1;
 
 	len = read (fd, buffer, BUFSIZ-1);
-	if (len < 0) return -1;
-
 	close (fd);
 
+	if (len < 0)
+	    return -1;
+
 	buffer [len] = '\0';
 
 	return 0;