Consistent use of abort() /* NOTREACHED */

This fixes some static analysis warnings:
PBD::fatal transmitter needs to be connected to a function
that aborts. This is usually the case with GUI

libs/ardour/audiosource.cc

@@ -396,7 +396,7 @@ AudioSource::read_peaks_with_fpp (PeakData *peaks, samplecnt_t npeaks, samplepos
 			}
 			if (statbuf.st_size < expected_file_size) {
 				fatal << "peak file is still truncated after rebuild" << endmsg;
-				/*NOTREACHED*/
+				abort (); /*NOTREACHED*/
 			}
 		}
 	}

libs/ardour/disk_reader.cc

@@ -350,8 +350,8 @@ DiskReader::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
 					internal_playback_seek (start_sample - playback_sample);
 				} else {
 					cerr << owner()->name() << " playback at " << speed << " not possible: ss = " << start_sample << " ps = " << playback_sample << endl;
-					abort (); // XXX -- now what?
-					/*NOTREACHED*/
+					// XXX -- now what?
+					abort (); /*NOTREACHED*/
 				}
 			}
 

libs/ardour/session.cc

@@ -3345,7 +3345,7 @@ Session::new_route_from_template (uint32_t how_many, PresentationInfo::order_t i
 
 				if (!find_route_name (name_base.c_str(), ++number, name, (being_added > 1))) {
 					fatal << _("Session: UINT_MAX routes? impossible!") << endmsg;
-					/*NOTREACHED*/
+					abort(); /*NOTREACHED*/
 				}
 
 			} else {

libs/ardour/transport_master_manager.cc

@@ -133,7 +133,7 @@ TransportMasterManager::instance()
 {
 	if (!_instance) {
 		fatal << string_compose (_("programming error:%1"), X_("TransportMasterManager::instance() called without an instance!")) << endmsg;
-		/* NOTREACHED */
+		abort (); /* NOTREACHED */
 	}
 	return *_instance;
 }

libs/pbd/debug.cc

@@ -87,8 +87,7 @@ PBD::new_debug_bit (const char* name)
 
 	if (_debug_bit >= debug_bits.size()) {
 		cerr << "Too many debug bits defined, offender was " << name << endl;
-		abort ();
-		/*NOTREACHED*/
+		abort (); /*NOTREACHED*/
 	}
 
 	ret.set (_debug_bit++, 1);

libs/surfaces/mackie/gui.cc

@@ -371,7 +371,7 @@ MackieControlProtocolGUI::device_dependent_widget ()
 
 			if (!surface) {
 				PBD::fatal << string_compose (_("programming error: %1\n"), string_compose ("n=%1 surface not found!", n)) << endmsg;
-				/*NOTREACHED*/
+				abort (); /*NOTREACHED*/
 			}
 
 			Gtk::ComboBox* input_combo = manage (new Gtk::ComboBox);

libs/surfaces/us2400/gui.cc

@@ -275,7 +275,7 @@ US2400ProtocolGUI::device_dependent_widget ()
 
 		if (!surface) {
 			PBD::fatal << string_compose (_("programming error: %1\n"), string_compose ("n=%1 surface not found!", n)) << endmsg;
-			/*NOTREACHED*/
+			abort (); /*NOTREACHED*/
 		}
 
 		Gtk::ComboBox* input_combo = manage (new Gtk::ComboBox);