Install into the proper directories.

--- doc/Makefile.in.orig
+++ doc/Makefile.in
@@ -162,8 +162,8 @@
 #CLEANFILES = texi2html.ps texi2html.pdf texi2html.html \
 #             texi2html.ascii
 #
-texinfodata = $(datadir)/texinfo
-texinfohtmldir = $(texinfodata)/html
+texinfodata = $(datadir)/doc/texi2html
+texinfohtmldir = $(texinfodata)
 texinfohtml_DATA = texi2html.html
 
 # use the script out of the distribution NOT
