Fix pointer arithmetic in EKF logging
Fix pointer arithmetic in EKF logging

* sizeof returns byte, but buf.estimator_status.states and
  buf.estimator_status.covariances are float pointers

dagar/Firmware,darknight-007/Firmware,acfloria/Firmware,krbeverx/Firmware,mcgill-robotics/Firmware,Aerotenna/Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,Aerotenna/Firmware,darknight-007/Firmware,acfloria/Firmware,mcgill-robotics/Firmware,Aerotenna/Firmware,krbeverx/Firmware,jlecoeur/Firmware,dagar/Firmware,darknight-007/Firmware,darknight-007/Firmware,jlecoeur/Firmware,acfloria/Firmware,dagar/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,mcgill-robotics/Firmware,dagar/Firmware,mcgill-robotics/Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,jlecoeur/Firmware,acfloria/Firmware,mcgill-robotics/Firmware,PX4/Firmware,jlecoeur/Firmware,mcgill-robotics/Firmware,krbeverx/Firmware,jlecoeur/Firmware,mcgill-robotics/Firmware,jlecoeur/Firmware,PX4/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,jlecoeur/Firmware,krbeverx/Firmware,darknight-007/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,PX4/Firmware,PX4/Firmware,dagar/Firmware,Aerotenna/Firmware,PX4/Firmware,PX4/Firmware,dagar/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,jlecoeur/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware