jdupes: ensure dedup functionality is enabled

CFLAGS set from the command line overrides
the logic to enable the dedup functionality

srcpkgs/jdupes/template

@@ -12,6 +12,15 @@ changelog="https://raw.githubusercontent.com/jbruchon/jdupes/master/CHANGES"
 distfiles="https://github.com/jbruchon/jdupes/archive/v${version}.tar.gz"
 checksum=bb7c53cd463ab5e21da85948c4662a3b7ac9b038ae993cc14ccf793d2472e2e9
 
+pre_build() {
+	sed -i 's/^CFLAGS +=/override CFLAGS +=/g' Makefile
+	sed -i 's/^LDFLAGS =/override LDFLAGS +=/g' Makefile
+}
+
 post_install() {
 	vlicense LICENSE
 }
+
+do_check() {
+	./jdupes -V|grep fsdedup
+}