Code cleanup for TANGODEVIC-57

Mostly exception handling

src/XPSAxis.cpp

@@ -450,8 +450,7 @@ void XPSAxis::write_backlashEnabled(Tango::WAttribute &attr)
 		//- deactivation of backlash compensation
 		this->positioner->disable_backlash();
 	}
-// if no exception 
-	// set read part of attribute;
+// if no exception raised then set read part of attribute;
 	m_backlashEnabled= new_backlashEnabled;
 
 	//- memorize backlashEnabled