make: fix info-files target

aed4be33 broke this command, since the regular expressions here register
the macros that were introduced there, too. With this patch the skipping
of apps in travis works properly again.

Makefile.buildtests

@@ -261,15 +261,15 @@ info-files: QUITE := 0
 info-files:
 	@( \
 		echo "$(abspath $(shell echo "$(MAKEFILE_LIST)"))" | tr ' ' '\n'; \
-		CSRC="$$($(MAKE) USEPKG="" -Bn | grep -o -e "[^ ]\+\.[csS]$$" -e "[^ ]\+\.[csS][ \']")"; \
+		CSRC="$$($(MAKE) USEPKG="" -Bn | grep -o -e "[^ ]\+\.[csS]$$" -e "[^ ]\+\.[csS][ \']" | grep -v -e "^\s*-D")"; \
 		echo "$$CSRC"; \
 		echo "$(RIOTBASE)/Makefile.base"; \
-		echo "$$CSRC" | xargs dirname | sort | uniq | xargs -I{} find {} -name "Makefile*"; \
+		echo "$$CSRC" | xargs dirname -- | sort | uniq | xargs -I{} find {} -name "Makefile*"; \
 		echo "$$CSRC" | xargs $(CC) $(CFLAGS) $(INCLUDES) -MM 2> /dev/null | grep -o "[^ ]\+\.h"; \
 		if [ -n "$$SRCXX" ]; then \
-			CPPSRC="$$($(MAKE) -Bn USEPKG="" | grep -o -e "[^ ]\+\.cpp")"; \
+			CPPSRC="$$($(MAKE) -Bn USEPKG="" | grep -o -e "[^ ]\+\.cpp" | grep -v -e "^\s*-D")"; \
 			echo "$$CPPSRC"; \
-			echo "$$CPPSRC" | xargs dirname | sort | uniq | xargs -I{} find {} -name "Makefile*"; \
+			echo "$$CPPSRC" | xargs dirname -- | sort | uniq | xargs -I{} find {} -name "Makefile*"; \
 			echo "$$CPPSRC" | xargs $(CXX) $(CXXFLAGS) $(INCLUDES) -MM 2> /dev/null | grep -o "[^ ]\+\.h"; \
 		fi; \
 		$(foreach pkg,$(USEPKG),find $(RIOTBASE)/pkg/$(pkg) -type f;) \