intel: Fix glClear behavior versus display lists.

The CALL_DrawArrays was leaking the clear's primitives into the display
list with GL_COMPILE_AND_EXECUTE.  Use _mesa_DrawArrays instead, which
doesn't appear to leak.  Fixes piglit dlist-clear test.

src/mesa/drivers/dri/intel/intel_clear.c

@@ -264,7 +264,7 @@ intel_clear_tris(GLcontext *ctx, GLbitfield mask)
 	 _mesa_Disable(GL_STENCIL_TEST);
       }
 
-      CALL_DrawArrays(ctx->Exec, (GL_TRIANGLE_FAN, 0, 4));
+      _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4);
 
       mask &= ~this_mask;
    }