drm/amdgpu: fix type for wptr in ring backup

Needs to be a u64.

Fixes: 77cc0da39c7c ("drm/amdgpu: track ring state associated with a fence")
Reviewed-by: Christian König <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
(cherry picked from commit 56fff1941abd3ca3b6f394979614ca7972552f7f)

drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c

···
 }
 
 static void amdgpu_ring_backup_unprocessed_command(struct amdgpu_ring *ring,
-						   u64 start_wptr, u32 end_wptr)
+						   u64 start_wptr, u64 end_wptr)
 {
 	unsigned int first_idx = start_wptr & ring->buf_mask;
 	unsigned int last_idx = end_wptr & ring->buf_mask;