fix some potential problems.

docs/Makefile.am

@@ -9,6 +9,10 @@ noinst_SCRIPTS = $(HELP2MAN) $(SRC2TEXI)
 EXTRA_DIST = menu.lst $(man_MANS) $(noinst_SCRIPTS) \
 	$(EXAMPLES) $(multiboot_TEXINFOS)
 
+# Cancel the rule %.texi -> %. This rule may confuse make to determine
+# the dependecies.
+.texi:
+
 %.c.texi: %.c $(srcdir)/$(SRC2TEXI)
 	/bin/sh $(srcdir)/$(SRC2TEXI) $(srcdir) $< $@
 

docs/Makefile.in

@@ -168,11 +168,6 @@ DVIPS = dvips
 	TEXINPUTS=$(srcdir):$$TEXINPUTS \
 	  MAKEINFO='$(MAKEINFO) -I $(srcdir)' $(TEXI2DVI) $<
 
-.texi:
-	@cd $(srcdir) && rm -f $@ $@-[0-9] $@-[0-9][0-9]
-	cd $(srcdir) \
-	  && $(MAKEINFO) `echo $< | sed 's,.*/,,'`
-
 .texinfo.info:
 	@cd $(srcdir) && rm -f $@ $@-[0-9] $@-[0-9][0-9]
 	cd $(srcdir) \
@@ -407,6 +402,8 @@ distclean-generic clean-generic maintainer-clean-generic clean \
 mostlyclean distclean maintainer-clean
 
 
+.texi:
+
 %.c.texi: %.c $(srcdir)/$(SRC2TEXI)
 	/bin/sh $(srcdir)/$(SRC2TEXI) $(srcdir) $< $@