glsl: Remove unused includes in link_uniform_block_active_visitor.h

Found with IWYU, compile-tested on my Ivy-bridge system.
This is not used in the header, and is included in the source.

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Thomas Helland <thomashelland90@gmail.com>

src/glsl/link_uniform_block_active_visitor.h

@@ -26,8 +26,6 @@
 #define LINK_UNIFORM_BLOCK_ACTIVE_VISITOR_H
 
 #include "ir.h"
-#include "ir_visitor.h"
-#include "glsl_types.h"
 #include "main/hash_table.h"
 
 struct link_uniform_block_active {