crypto: qat - fix a signedness bug in get_service_enabled()

crypto: qat - fix a signedness bug in get_service_enabled()

[ Upstream commit 844318dfd31f7c99f6cebbdba5d6f8392c4c115c ]

The "ret" variable needs to be signed or there is an error message which
will not be printed correctly.

Fixes: 0cec19c761e5 ("crypto: qat - add support for compression for 4xxx")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>