doc: inslist.src is an intermediate file, move to "make clean"

inslist.src is an intermediate file, it should be in "make clean"
rather than "make spotless"; otherwise it ends up in the xdoc tarball.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

doc/Makefile.in

@@ -88,11 +88,12 @@ nasm.inf: nasmdoc.ipf
 clean:
 	-rm -f *.rtf *.hpj *.texi *.gid *.ipf *.dip
 	-rm -f *.aux *.cp *.fn *.ky *.pg *.log *.toc *.tp *.vr
+	-rm -f inslist.src
 
 spotless: clean
 	-rm -rf html info
 	-rm -f *.hlp nasmdoc.txt *.inf *.pdf *.dvi
-	-rm -f nasmdoc*.ps inslist.src
+	-rm -f nasmdoc*.ps
 
 install: all
 	mkdir -p $(INSTALLROOT)$(infodir)