Fixes issue #2568

When surrounding the version with quotes, even no version (an empty
string) will be accepted as parameter. The install.sh script treats an
empty version string the same as no when version is set. So it will
then just use the latest available version.

builtin/provisioners/chef/linux_provisioner.go

@@ -33,7 +33,7 @@ func (p *Provisioner) linuxInstallChefClient(
 	}
 
 	// Then execute the install.sh scrip to download and install Chef Client
-	err = p.runCommand(o, comm, fmt.Sprintf("%sbash ./install.sh -v %s", prefix, p.Version))
+	err = p.runCommand(o, comm, fmt.Sprintf("%sbash ./install.sh -v %q", prefix, p.Version))
 	if err != nil {
 		return err
 	}