tools/env: use host build flags

Convert the tools/env/Makefile to use the same host tool syntax as the
other tool subdirs.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

tools/env/Makefile

@@ -26,16 +26,16 @@ include $(TOPDIR)/config.mk
 SRCS	:= $(obj)crc32.c  fw_env.c  fw_env_main.c
 HEADERS	:= fw_env.h
 
-CPPFLAGS := -Wall -DUSE_HOSTCC -I$(SRCTREE)/include
+HOSTCFLAGS += -Wall -DUSE_HOSTCC -I$(SRCTREE)/include
 
 ifeq ($(MTD_VERSION),old)
-CPPFLAGS += -DMTD_OLD
+HOSTCFLAGS += -DMTD_OLD
 endif
 
 all:	$(obj)fw_printenv
 
 $(obj)fw_printenv:	$(SRCS) $(HEADERS)
-	$(CROSS_COMPILE)gcc $(CPPFLAGS) $(SRCS) -o $(obj)fw_printenv
+	$(HOSTCC) $(HOSTCFLAGS) $(HOSTLDFLAGS) -o $@ $(SRCS)
 
 clean:
 	rm -f $(obj)fw_printenv $(obj)crc32.c