Fix compile problem with new env code.

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index bf9d506..e083a5b 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -35,6 +35,7 @@
 #ifdef MTD_OLD
 # include <linux/mtd/mtd.h>
 #else
+# define  __user	/* nothing */
 # include <mtd/mtd-user.h>
 #endif