intel: Call intel_prepare_render() in intelClear()

Make sure we have up to date buffers before we start looking at
the tiling bits to determine how to clear.

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

@@ -247,8 +247,6 @@ intelClearWithBlit(GLcontext *ctx, GLbitfield mask)
    GLuint buf;
    all = (cw == fb->Width && ch == fb->Height);
 
-   intel_prepare_render(intel);
-
    /* Loop over all renderbuffers */
    for (buf = 0; buf < BUFFER_COUNT && mask; buf++) {
       const GLbitfield bufBit = 1 << buf;

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

@@ -90,6 +90,10 @@ intelClear(GLcontext *ctx, GLbitfield mask)
       tri_mask |= (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT));
    }
 
+   /* Make sure we have up to date buffers before we start looking at
+    * the tiling bits to determine how to clear. */
+   intel_prepare_render(intel);
+
    /* HW stencil */
    if (mask & BUFFER_BIT_STENCIL) {
       const struct intel_region *stencilRegion