env: sf: Put ENV_INVALID into gd->env_valid on CRC failure

env_sf_init_addr() says the environment is valid even if it is assigning
default environment due to CRC failure. Change this to ENV_INVALID and
let the generic env_init() function, which calls this initializer,
assign the default environment.
Signed-off-by: NMarek Behún <marek.behun@nic.cz>
Reviewed-by: NSimon Glass <sjg@chromium.org>

env/sf.c

@@ -341,8 +341,7 @@ static int env_sf_init_addr(void)
 		gd->env_addr = (ulong)&(env_ptr->data);
 		gd->env_valid = ENV_VALID;
 	} else {
-		gd->env_addr = (ulong)&default_environment[0];
-		gd->env_valid = ENV_VALID;
+		gd->env_valid = ENV_INVALID;
 	}
 
 	return 0;