env: Inline env_get_char() into its only user

This function is a relic from the past when environment was read from
underlying device one character at a time.

It is used only in the case when getting an environemnt variable prior
relocation, and the function is simple enough to be inlined there.

Since env_get_char() is being changed to simple access to an array, we
can drop the failing cases and simplify the code (this could have been
done before, since env_get_char() did not fail even before).

Signed-off-by: Marek Behún <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>

env/env.c

@@ -166,14 +166,6 @@ static struct env_driver *env_driver_lookup(enum env_operation op, int prio)
 	return drv;
 }
 
-int env_get_char(int index)
-{
-	if (gd->env_valid == ENV_INVALID)
-		return default_environment[index];
-	else
-		return *(uchar *)(gd->env_addr + index);
-}
-
 int env_load(void)
 {
 	struct env_driver *drv;