On error, pthread_create() returns a positive number (errno).
Fix the test on the return value.
Fixes: af1475918124 ("vhost: introduce API to start a specific driver")
Fixes: e623e0c6d8a5 ("vhost: add reconnect ability")
Cc: stable@dpdk.org
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
da51d2f6b8