Build project after clean

Currently the mojo reports probably old warnings, because of this we
need to rebuild the project after cleanups are applied to get a more
up-to-date state to report.

(cherry picked from commit 97aef82)

tycho-cleancode-plugin/src/main/java/org/eclipse/tycho/cleancode/CleanUp.java

@@ -65,6 +65,7 @@ protected CleanupResult createResult(IProject project) throws Exception {
 				applyCleanups(project, cleanups, units);
 			}
 		}
+		buildProject(project);
 		return result;
 	}