Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

This avoids a use-after-free in case the driver is later unbound.

Fixes: d2efbbd1 ("gnss: add driver for sirfstar-based receivers")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
[ johan: amend commit message; mention potential use-after-free ]
Cc: stable <stable@vger.kernel.org>	# 4.19
Signed-off-by: Johan Hovold <johan@kernel.org>