tools: remove unused ret

Remove unused ret from fw_env_flush.

Signed-off-by: Jelle van der Waa <jelle@vdwaa.nl>
Reviewed-by: Simon Glass <sjg@chromium.org>

tools/env/fw_env.c

@@ -505,8 +505,6 @@ int fw_printenv(int argc, char *argv[], int value_only, struct env_opts *opts)
 
 int fw_env_flush(struct env_opts *opts)
 {
-	int ret;
-
 	if (!opts)
 		opts = &default_opts;