anv: fix uninitialized use of compute initialization batch

We sometimes fail initialization.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: 09d12e6727 ("anv: Add support for I915_ENGINE_CLASS_COMPUTE in init_device_state()")
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25891>
diff --git a/src/intel/vulkan/genX_init_state.c b/src/intel/vulkan/genX_init_state.c
index f8bab0c..c0ca960 100644
--- a/src/intel/vulkan/genX_init_state.c
+++ b/src/intel/vulkan/genX_init_state.c
@@ -599,12 +599,13 @@
 static VkResult
 init_compute_queue_state(struct anv_queue *queue)
 {
-   struct anv_batch batch;
    UNUSED const struct intel_device_info *devinfo = queue->device->info;
-
    uint32_t cmds[64];
-   batch.start = batch.next = cmds;
-   batch.end = (void *) cmds + sizeof(cmds);
+   struct anv_batch batch = {
+      .start = cmds,
+      .next = cmds,
+      .end = (void *) cmds + sizeof(cmds),
+   };
 
    genX(emit_pipeline_select)(&batch, GPGPU);