Move exception raising back into retryable block in VirtualBox driver command execution

By moving the exception throwing back into the retryable block it actually enables the retryable to function properly by retrying, if appropriate, when an certain exception is raised.

plugins/providers/virtualbox/driver/base.rb

@@ -284,10 +284,10 @@ module VagrantPlugins
           # Variable to store our execution result
           r = nil
 
-          # If there is an error with VBoxManage, this gets set to true
-          errored = false
-
           retryable(:on => Vagrant::Errors::VBoxManageError, :tries => tries, :sleep => 1) do
+            # If there is an error with VBoxManage, this gets set to true
+            errored = false
+            
             # Execute the command
             r = raw(*command, &block)
 
@@ -322,14 +322,14 @@ module VagrantPlugins
                 errored = true
               end
             end
-          end
-
-          # If there was an error running VBoxManage, show the error and the
-          # output.
-          if errored
-            raise Vagrant::Errors::VBoxManageError,
-              :command => command.inspect,
-              :stderr  => r.stderr
+            
+            # If there was an error running VBoxManage, show the error and the
+            # output.
+            if errored
+              raise Vagrant::Errors::VBoxManageError,
+                :command => command.inspect,
+                :stderr  => r.stderr
+            end
           end
 
           # Return the output, making sure to replace any Windows-style