variables: Fix two typos in InheritValue().

First one is about starting to inherit from the parent. Shouldn't hurt much.
Second one is about looking to inherit from the right variable. hurt more.

src/misc/variables.c

@@ -1404,8 +1404,8 @@ static int InheritValue( vlc_object_t *p_this, const char *psz_name,
                          vlc_value_t *p_val, int i_type )
 {
     i_type &= VLC_VAR_CLASS;
-    for( vlc_object_t *obj = p_this; obj != NULL; obj = obj->p_parent )
-        if( var_GetChecked( p_this, psz_name, i_type, p_val ) == VLC_SUCCESS )
+    for( vlc_object_t *obj = p_this->p_parent; obj != NULL; obj = obj->p_parent )
+        if( var_GetChecked( obj, psz_name, i_type, p_val ) == VLC_SUCCESS )
             return VLC_SUCCESS;
 
     /* else take value from config */