Makefile: simplify silent cleaning

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
diff --git a/src/Makefile b/src/Makefile
index ec5d3a6..341a90e 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -67,18 +67,14 @@
 BUILT_IN_COMPILE.c := $(COMPILE.c)
 COMPILE.c = @echo "  CC      $@";
 COMPILE.c += $(BUILT_IN_COMPILE.c)
+BUILT_IN_RM := $(RM)
+RM := @a() { echo "  CLEAN   $$@"; $(BUILT_IN_RM) "$$@"; }; a
 endif
 
 wg: $(sort $(patsubst %.c,%.o,$(wildcard *.c)))
 
-ifneq ($(V),1)
-clean:
-	@echo "  CLEAN   {wg,*.o,*.d}"
-	@$(RM) wg *.o *.d
-else
 clean:
 	$(RM) wg *.o *.d
-endif
 
 install: wg
 	@install -v -d "$(DESTDIR)$(BINDIR)" && install -v -m 0755 wg "$(DESTDIR)$(BINDIR)/wg"