Check if DISTNAME subdir has a Makefile

When trying to install platform specific scripts make sure the
platform specific DISTNAME subdir has a Makefile (which also
checks if the dir even exists.) This should help for platforms
like altlinux where we set the DISTNAME but for which we don't
have any platform specific scripts.

platforms/Makefile.in

@@ -24,31 +24,31 @@ all:
 	done
 
 install:
-	@if test x$(DISTNAME) != x ; then \
+	@if test x$(DISTNAME) != x -a -f $(DISTNAME)/Makefile ; then \
 	   (cd $(DISTNAME); \
 	      $(MAKE) DESTDIR=$(DESTDIR) "DISTNAME=$(DISTNAME)" "DISTVER=$(DISTVER)" $@) \
 	fi
 
 install-autostart:
-	@if test x$(DISTNAME) != x ; then \
+	@if test x$(DISTNAME) != x -a -f $(DISTNAME)/Makefile ; then \
 	   (cd $(DISTNAME); \
 	      $(MAKE) DESTDIR=$(DESTDIR) "DISTNAME=$(DISTNAME)" "DISTVER=$(DISTVER)" $@) \
 	fi
 
 install-autostart-dir:
-	@if test x$(DISTNAME) != x ; then \
+	@if test x$(DISTNAME) != x -a -f $(DISTNAME)/Makefile ; then \
 	   (cd $(DISTNAME); \
 	      $(MAKE) DESTDIR=$(DESTDIR) "DISTNAME=$(DISTNAME)" "DISTVER=$(DISTVER)" $@) \
 	fi
 
 install-autostart-fd:
-	@if test x$(DISTNAME) != x ; then \
+	@if test x$(DISTNAME) != x -a -f $(DISTNAME)/Makefile ; then \
 	   (cd $(DISTNAME); \
 	      $(MAKE) DESTDIR=$(DESTDIR) "DISTNAME=$(DISTNAME)" "DISTVER=$(DISTVER)" $@) \
 	fi
 
 install-autostart-sd:
-	@if test x$(DISTNAME) != x ; then \
+	@if test x$(DISTNAME) != x -a -f $(DISTNAME)/Makefile ; then \
 	   (cd $(DISTNAME); \
 	      $(MAKE) DESTDIR=$(DESTDIR) "DISTNAME=$(DISTNAME)" "DISTVER=$(DISTVER)" $@) \
 	fi