glsl: add arrays of arrays support to without_array function

Signed-off-by: Timothy Arceri <t_arceri@yahoo.com.au>
Reviewed-by: Ilia Mirkin <imirkin@alum.mit.edu>

src/glsl/glsl_types.h

@@ -540,7 +540,12 @@ struct glsl_type {
     */
    const glsl_type *without_array() const
    {
-      return this->is_array() ? this->fields.array : this;
+      const glsl_type *t = this;
+
+      while (t->is_array())
+         t = t->fields.array;
+
+      return t;
    }
 
    /**