vfs: use inodeToBytes to generate file handle for chimera

inodeToBytes encapsulate generation of byte array
representation of FsInode.

Acked-by: Gerd Behrmann
Target: master, 0.5
(cherry picked from commit 2e6e17c559c19b5b82a782edeea73a1b8bfe4231)
Signed-off-by: Tigran Mkrtchyan <tigran.mkrtchyan@desy.de>