Fix example scripts build dependencies

Currently, the example scripts (the init.d and the cron script) do not
depend on the Makefile, so if configure is rerun with different
parameters these scripts are not rebuild.

The patch adds Makefile as a dependency so changes to installation paths
or other parameters trigger the rebuild.

Reviewed-by: imsnah

doc/examples/Makefile.am

@@ -4,7 +4,7 @@ CLEANFILES = $(nodist_EXTRA_DATA)
 nodist_EXTRA_DATA = ganeti.initd ganeti.cron
 
 all-local: ganeti.initd ganeti.cron
-ganeti.%: ganeti.%.in
+ganeti.%: ganeti.%.in Makefile
 	sed \
 	  -e "s#@PREFIX@#$(prefix)#g" \
 	  -e "s#@SYSCONFDIR@#$(sysconfdir)#g" \