glsl: make _mesa_builtin_uniform_desc static

I can't see any reason this is global (unless for debugging)

Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/src/glsl/builtin_variables.cpp b/src/glsl/builtin_variables.cpp
index 03b64c9..353805b 100644
--- a/src/glsl/builtin_variables.cpp
+++ b/src/glsl/builtin_variables.cpp
@@ -328,7 +328,7 @@
 
 #define STATEVAR(name) {#name, name ## _elements, Elements(name ## _elements)}
 
-const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
+static const struct gl_builtin_uniform_desc _mesa_builtin_uniform_desc[] = {
    STATEVAR(gl_DepthRange),
    STATEVAR(gl_ClipPlane),
    STATEVAR(gl_Point),