Makefile: Add '+' to QUIET_SUBDIR0 to fix parallel make.

Signed-off-by: Fernando J. Pereda <ferdy@gentoo.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Makefile

@@ -641,7 +641,7 @@ ifeq ($(TCLTK_PATH),)
 NO_TCLTK=NoThanks
 endif
 
-QUIET_SUBDIR0  = $(MAKE) -C # space to separate -C and subdir
+QUIET_SUBDIR0  = +$(MAKE) -C # space to separate -C and subdir
 QUIET_SUBDIR1  =
 
 ifneq ($(findstring $(MAKEFLAGS),w),w)
@@ -657,7 +657,7 @@ ifndef V
 	QUIET_LINK     = @echo '   ' LINK $@;
 	QUIET_BUILT_IN = @echo '   ' BUILTIN $@;
 	QUIET_GEN      = @echo '   ' GEN $@;
-	QUIET_SUBDIR0  = @subdir=
+	QUIET_SUBDIR0  = +@subdir=
 	QUIET_SUBDIR1  = ;$(NO_SUBDIR) echo '   ' SUBDIR $$subdir; \
 			 $(MAKE) $(PRINT_DIR) -C $$subdir
 	export V