Fixed bug.

Rev: bin/install.pike:1.13

bin/install.pike

@@ -342,7 +342,9 @@ int main(int argc, string *argv)
 	exit(1);
       }
     }
+    if (old_exec_prefix) {
       mkdirhier(old_exec_prefix);
+    }
     symlink(pike,lnk);
   }
 #endif