ecc/Makefile.in: fix target clean

After renaming OBJECTS to ECC_OBJECTS, the clean target was not
updated.

Change-Id: I0b70e1875d46e59d5df51e78176b09672f285ab7
diff --git a/ecc/Makefile.in b/ecc/Makefile.in
index 2ba17a1..ebf8231 100644
--- a/ecc/Makefile.in
+++ b/ecc/Makefile.in
@@ -59,7 +59,7 @@
 	echo top_builddir: $(top_builddir)
 
 clean:
-	@rm -f $(PROGRAMS) main.o $(LIB) $(OBJECTS)
+	@rm -f $(PROGRAMS) main.o $(LIB) $(ECC_OBJECTS)
 	for dir in $(SUBDIRS); do \
 		$(MAKE) -C $$dir clean ; \
 	done