nir: fix yet another MSVC build break

Trivial.

src/compiler/nir/nir_gather_xfb_info.c

@@ -138,7 +138,7 @@ nir_gather_xfb_info(const nir_shader *shader, void *mem_ctx)
          compare_xfb_output_offsets);
 
    /* Finally, do a sanity check */
-   unsigned max_offset[NIR_MAX_XFB_BUFFERS] = { };
+   unsigned max_offset[NIR_MAX_XFB_BUFFERS] = {0};
    for (unsigned i = 0; i < xfb->output_count; i++) {
       assert(xfb->outputs[i].offset >= max_offset[xfb->outputs[i].buffer]);
       assert(xfb->outputs[i].component_mask != 0);