makefile: handle missing directory

tools/Makefile

@@ -1,5 +1,6 @@
-BIN = bin
-OBJ = obj
+BIN  = bin
+OBJ  = obj
+DIRS = $(BIN) $(OBJ)
 CFLAGS = -g -O -W -Wall
 
 BINS         = $(addprefix $(BIN)/, unmunge munge repair)
@@ -7,6 +8,8 @@ UNMUNGE_OBJS = $(addprefix $(OBJ)/, util.o unmunge.o)
 MUNGE_OBJS   = $(addprefix $(OBJ)/, util.o munge.o)
 REPAIR_OBJS  = $(addprefix $(OBJ)/, util.o heap.o mempool.o subst.o repair.o)
 
+$(shell mkdir -p $(DIRS))
+
 all: $(BINS)
 
 $(BIN)/unmunge: $(UNMUNGE_OBJS)
@@ -25,4 +28,4 @@ clean:
 	rm -f $(OBJ)/* $(BIN)/*.core
 
 cleaner:
-	rm -f $(BIN)/* $(OBJ)/* $(BIN)/*.core
+	rm -rf $(DIRS)