Fix broken make clean target

Makefile

@@ -27,7 +27,7 @@ render_srv_doc:
 	pdflatex -output-directory build ${SRV_DOC_NAME}.tex
 
 clean:
-	cd build; rm -v *.aux *.bbl *.blg *.log *.out *.toc
+	cd build; rm -v *.aux *.bbl *.blg *.log *.out *.toc *.synctex.gz; exit 0;
 
 cleanall:
 	rm -rfv build; mkdir build