Clear mountPoint string when selecting a non-mountable filesystem type.

CAL-249 #close I pushed a fix, please test and reopen if still broken.

src/modules/partition/gui/CreatePartitionDialog.cpp

@@ -160,6 +160,8 @@ CreatePartitionDialog::updateMountPointUi()
     }
     m_ui->mountPointLabel->setEnabled( enabled );
     m_ui->mountPointComboBox->setEnabled( enabled );
+    if ( !enabled )
+        m_ui->mountPointComboBox->setCurrentText( QString() );
 }
 
 void