net/ixgbe: fix resource leak after thread exits normally

net/ixgbe: fix resource leak after thread exits normally

When the thread exits normally, pthread_join() is not called, which can
result in a resource leak. Therefore, the thread is set to separation
mode using function pthread_detach(), so that no program call
pthread_join() is required to recycle, and when the thread exits,
the system automatically reclaims resources.

Wait for the thread to finish with timeout argument(0 means that it will
not return until link complete), wait until the thread finishes before
returning. Normally, the thread will finish in a shorter time, and give
a warning message if it hasn't finished in a longer time.

Fixes: 819d0d1d57f1 ("net/ixgbe: fix blocking system events")
Cc: stable@dpdk.org
Signed-off-by: Tao Zhu <taox.zhu@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Reviewed-by: Xiaolong Ye <xiaolong.ye@intel.com>