Land rapid7#4267, CheckCode fix for vmware_mount

Author: wvu

modules/exploits/linux/local/vmware_mount.rb

@@ -64,7 +64,7 @@ def check
   end
 
   def exploit
-    unless check == CheckCode::Vulnerable
+    unless check == CheckCode::Appears
       fail_with(Failure::NotVulnerable, "vmware-mount doesn't exist or is not setuid")
     end