crocus: fix off-by-one error when clearing stale syncobjs

This is the same fix as commit 1311eddd

 ("iris: fix off-by-one error
when clearing stale syncobjs"), but for crocus.

Signed-off-by: Nicholas Bishop <nicholasbishop@google.com>
Part-of: <!19282>

src/gallium/drivers/crocus/crocus_fence.c

@@ -127,7 +127,7 @@ clear_stale_syncobjs(struct crocus_batch *batch)
                                           struct drm_i915_gem_exec_fence));
 
    /* Skip the first syncobj, as it's the signalling one. */
-   for (int i = n - 1; i > 1; i--) {
+   for (int i = n - 1; i > 0; i--) {
       struct crocus_syncobj **syncobj =
          util_dynarray_element(&batch->syncobjs, struct crocus_syncobj *, i);
       struct drm_i915_gem_exec_fence *fence =