Makefile: replace __SESSION_NAME__ in the .tex by the session name

This allows to have __SESSION_NAME__ replaced even in verbatim
environments and \code{...} macros.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Makefile

@@ -178,6 +178,7 @@ LABS_PICTURES = $(call PICTURES,$(foreach s,$(LABS_CHAPTERS),labs/$(s))) $(COMMO
 	echo "\input{$(VARS)}" >> $(OUTDIR)/$(basename $@).tex
 	for f in $(filter %.tex,$^) ; do \
 		cp $$f $(OUTDIR)/`basename $$f` ; \
+		sed -i 's%__SESSION_NAME__%$(LABS_TRAINING)%' $(OUTDIR)/`basename $$f` ; \
 		printf "\input{%s}\n" `basename $$f .tex` >> $(OUTDIR)/$(basename $@).tex ; \
 	done
 	(cd $(OUTDIR); $(PDFLATEX_ENV) $(PDFLATEX) $(basename $@).tex)