i965: Drop unnecessary bo->align field.

bo->align is always 0; there's no need to waste 8 bytes storing it.
Thanks to C99 initializers zeroing fields, we can completely drop the
only read of the field altogether.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>

src/mesa/drivers/dri/i965/brw_bufmgr.c

@@ -320,7 +320,6 @@ retry:
          bo = LIST_ENTRY(struct brw_bo, bucket->head.prev, head);
          list_del(&bo->head);
          alloc_from_cache = true;
-         bo->align = 0;
       } else {
          /* For non-render-target BOs (where we're probably
           * going to map it first thing in order to fill it
@@ -381,7 +380,6 @@ retry:
       bo->gem_handle = create.handle;
 
       bo->bufmgr = bufmgr;
-      bo->align = 0;
 
       bo->tiling_mode = I915_TILING_NONE;
       bo->swizzle_mode = I915_BIT_6_SWIZZLE_NONE;

src/mesa/drivers/dri/i965/brw_bufmgr.h

@@ -56,13 +56,6 @@ struct brw_bo {
     */
    uint64_t size;
 
-   /**
-    * Alignment requirement for object
-    *
-    * Used for GTT mapping & pinning the object.
-    */
-   uint64_t align;
-
    /** Buffer manager context associated with this buffer object */
    struct brw_bufmgr *bufmgr;
 

src/mesa/drivers/dri/i965/intel_batchbuffer.c

@@ -170,7 +170,6 @@ add_exec_bo(struct intel_batchbuffer *batch, struct brw_bo *bo)
    batch->validation_list[batch->exec_count] =
       (struct drm_i915_gem_exec_object2) {
          .handle = bo->gem_handle,
-         .alignment = bo->align,
          .offset = bo->gtt_offset,
          .flags = bo->kflags,
       };