mesa: add parenthesis

(cherry picked from commit c366fd83b6)

src/mesa/main/dd.h

@@ -919,9 +919,9 @@ struct dd_function_table {
    void (*ValidateTnlModule)( GLcontext *ctx, GLuint new_state );
 
 
-#define PRIM_OUTSIDE_BEGIN_END   GL_POLYGON+1
-#define PRIM_INSIDE_UNKNOWN_PRIM GL_POLYGON+2
-#define PRIM_UNKNOWN             GL_POLYGON+3
+#define PRIM_OUTSIDE_BEGIN_END   (GL_POLYGON+1)
+#define PRIM_INSIDE_UNKNOWN_PRIM (GL_POLYGON+2)
+#define PRIM_UNKNOWN             (GL_POLYGON+3)
 
    /**
     * Set by the driver-supplied T&L engine.