env: correct overflow check of env_has_init size

Correct the overflow check of the bit-field env_has_init with
the max value of env_location= ENVL_COUNT and no more with the
size of env_locations.

This bit-field is indexed by this enumerate and not by the position in
the env_locations (only used in env_get_location) and the
2 values are different, depending of thea ctivated CONFIG_ENV_IS_ options.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

env/env.c

@@ -103,7 +103,7 @@ static void env_set_inited(enum env_location location)
 	 * using the above enum value as the bit index. We need to
 	 * make sure that we're not overflowing it.
 	 */
-	BUILD_BUG_ON(ARRAY_SIZE(env_locations) > BITS_PER_LONG);
+	BUILD_BUG_ON(ENVL_COUNT > BITS_PER_LONG);
 
 	gd->env_has_init |= BIT(location);
 }