Make sure you have installed a custom recovery before
./platform-tools/adb root ./platform-tools/adb push /tmp/cm-13.0-20160530-NIGHTLY-d802-recovery.img /data/ ./platform-tools/adb shell dd if=/data/cm-13.0-20160530-NIGHTLY-d802-recovery.img of=/dev/block/platform/msm_sdcc.1/by-name/recovery bs=1m rm /data/cm-13.0-20160530-NIGHTLY-d802-recovery.img exit ./platform-tools/adb reboot recovery
Check output of cat /proc/cmdline