Use configure-defined variable
--- disk-manager-1.0.1.orig/data/Makefile.am
+++ disk-manager-1.0.1/data/Makefile.am
@@ -16,7 +16,7 @@
 CLEANFILES = $(desktop_DATA)
 EXTRA_DIST = $(desktop_in_files)
 
-autostartdir = /etc/xdg/autostart
+autostartdir = $(sysconfdir)/xdg/autostart
 autostart_in_files = disk-manager-check.desktop.in
 autostart_DATA = $(autostart_in_files:.desktop.in=.desktop)
 CLEANFILES += $(autostart_DATA)
--- disk-manager-1.0.1.orig/data/Makefile.in
+++ disk-manager-1.0.1/data/Makefile.in
@@ -198,7 +198,7 @@
 
 EXTRA_DIST = $(desktop_in_files) $(autostart_in_files) $(pkgdata_DATA) $(man_MANS)
 
-autostartdir = /etc/xdg/autostart
+autostartdir = $(sysconfdir)/xdg/autostart
 autostart_in_files = disk-manager-check.desktop.in
 autostart_DATA = $(autostart_in_files:.desktop.in=.desktop)