BlockingQueue: default initialize _data
BlockingQueue: default initialize _data

This was reported by coverity.

acfloria/Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,PX4/Firmware,acfloria/Firmware,krbeverx/Firmware,dagar/Firmware,acfloria/Firmware,PX4/Firmware,acfloria/Firmware,PX4/Firmware,krbeverx/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,dagar/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,PX4/Firmware,dagar/Firmware,PX4/Firmware,krbeverx/Firmware,acfloria/Firmware,acfloria/Firmware,PX4/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,dagar/Firmware