glsl: Move Doxygen block closing ot the correct place

This is the closing for the "\defgroup IR Intermediate representation
nodes" all the way at the top of the file.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/ir.h

@@ -2186,8 +2186,6 @@ private:
    ir_constant(void);
 };
 
-/*@}*/
-
 /**
  * IR instruction to emit a vertex in a geometry shader.
  */
@@ -2235,6 +2233,8 @@ public:
    virtual ir_visitor_status accept(ir_hierarchical_visitor *);
 };
 
+/*@}*/
+
 /**
  * Apply a visitor to each IR node in a list
  */