Mikrotik RB750r2 sysupgrade Resource busy

Mikrotik RB750r2 (hEX lite)
Reboot (SNAPSHOT, r4049-9412fc2) The snapshot build dated 28/04/2017 (Europe timezone)

I first did a boot up on TFTP with mikrotik-rb-nor-flash-16M-initramfs-kernel.bin and then downloaded the lede-ar71xx-mikrotik-rb-nor-flash-16M-squashfs-sysupgrade.bin via wget into cd /tmp

Then i did sysupgrade lede-ar71xx-mikrotik-rb-nor-flash-16M-squashfs-sysupgrade.bin however everything seems to be installed ok but got theses following errors?

root@LEDE:/tmp# sysupgrade lede-ar71xx-mikrotik-rb-nor-flash-16M-squashfs-sysupgrade.bin
Cannot save config while running from ramdisk.
killall: watchdog: no process killed
Unlocking firmware ...
Erasing firmware ...
Sending TERM to remaining processes ... udhcpc odhcp6c ntpd dnsmasq ubusd askfirst logd netifd odhcpd
Sending KILL to remaining processes ... askfirst
Performing system upgrade...
Unlocking firmware ..
Writing from to firmware ...
Appending jffs2 data from /tmp/sysupgrade.tgz to firmware..
.File /tmp/sysupgrade.tgz does not exist
Upgrade completed
Rebooting system...
umount: can’t unmount /dev/pts: Resource busy
umount: can’t unmount /dev: Resource busy
umount: can’t unmount /tmp: Resource busy
umount: can’t unmount /: Invalid argument