hv_utils: Fix passing zero to 'PTR_ERR' warning

Sparse warn this:

drivers/hv/hv_util.c:753 hv_timesync_init() warn:
 passing zero to 'PTR_ERR'

Use PTR_ERR_OR_ZERO instead of PTR_ERR to fix this.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20210514070116.16800-1-yuehaibing@huawei.com
[ wei: change %ld to %d ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>