Fix VPATH builds

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5439 d4fa192b-c00b-0410-8231-f00ffab90ce4

doc/sphinx/Makefile.am

@@ -10,7 +10,7 @@ BUILDDIR      = =build
 # Internal variables.
 PAPEROPT_a4     = -D latex_paper_size=a4
 PAPEROPT_letter = -D latex_paper_size=letter
-ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) .
+ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) $(srcdir)
 
 .PHONY: help clean html dirhtml pickle json htmlhelp qthelp latex changes linkcheck doctest