ice: remove pointless NULL check of port_info

ice: remove pointless NULL check of port_info

The code in ice_sched_cleanup_all checks whether the port info is NULL
prior to calling ice_sched_clear_port. However, ice_sched_clear_port
already checks whether port info is non-NULL.

More importantly, it also checks whether the port structure has been
initialized by checking its port_state field as well.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>