get rid of a shell warning if md5sum is not found

SVN-Revision: 12494

include/scan.mk

@@ -52,7 +52,7 @@ $(TMP_DIR)/info/.files-$(SCAN_TARGET).mk: $(FILELIST)
 $(TARGET_STAMP)::
 	+( \
 		$(NO_TRACE_MAKE) $(FILELIST); \
-		MD5SUM=$$(cat $(FILELIST) | (md5sum || md5) | awk '{print $$1}'); \
+		MD5SUM=$$(cat $(FILELIST) | (md5sum || md5) 2>/dev/null | awk '{print $$1}'); \
 		[ -f "$@.$$MD5SUM" ] || { \
 			rm -f $@.*; \
 			touch $@.$$MD5SUM; \