Rename obj/ directory to objs/ to avoid BSD make issue.
diff --git a/configure.ac b/configure.ac
index 8925640..75561cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -444,13 +444,13 @@
 	test/metaflac-test-files/Makefile \
 	test/pictures/Makefile \
 	build/Makefile \
-	obj/Makefile \
-	obj/debug/Makefile \
-	obj/debug/bin/Makefile \
-	obj/debug/lib/Makefile \
-	obj/release/Makefile \
-	obj/release/bin/Makefile \
-	obj/release/lib/Makefile \
+	objs/Makefile \
+	objs/debug/Makefile \
+	objs/debug/bin/Makefile \
+	objs/debug/lib/Makefile \
+	objs/release/Makefile \
+	objs/release/bin/Makefile \
+	objs/release/lib/Makefile \
 ])
 AC_OUTPUT