Same error after upgrading OH2.3 to OH2.4 M5 on a rpi2. I still have to test before upgrading my rpi3 with my “big” environment, but I confirm this happening at least on rpi2.
It does not seem to be related to the binding itself. Same problem with both cc2531 and telegesis dongles, same “serial error: port /dev/ttyACM0 does not exist” (/dev/ttyUSB0 with my telegesis).
Solution (at least for my rpi2): installed liblockdev. It seems to be needed by the native part of nrjavaserial. It is not (or I could not find it) in my rasbpian distro, so I just downloaded and compiled it. Now it is working for me. How to compile if you do not find a binary package for your distro:
cd /tmp
wget http://ftp.de.debian.org/debian/pool/main/l/lockdev/lockdev_1.0.3.orig.tar.gz
tar zxvf lockdev_1.0.3.orig.tar.gz
cd lockdev-1.0.3/
make
make install
cd /usr/lib
ln -s /usr/local/lib/liblockdev.1.0.3.so
ln -s liblockdev.1.0.3.so liblockdev.so.1
ln -s liblockdev.so.1 liblockdev.so
And then restart openhab. Hope this helps, as it took me several hours googling without really finding a solution 
As a prove that it is now being used, so at least this has something to do with the issue :
#> fuser /usr/local/lib/liblockdev.1.0.3.so
/usr/local/lib/liblockdev.1.0.3.so: 29759m
#> ps -ef | grep 29759
openhab 29759 1 8 05:13 ? 00:12:23 /usr/lib/java/jre8/bin/java -Dopenhab.home=/usr/share/openhab2 -Dopenhab.conf=/etc/openhab2 ...
Pedro