fusefs: fix FUSE_CREATE with file handles and fuse protocol < 7.9

Prior to fuse protocol version 7.9, the fuse_entry_out structure had a
smaller size. But fuse_vnop_create did not take that into account when
working with servers that use older protocols. The bug does not matter
for servers which don't use file handles or open flags (the only fields
affected).

PR: 263625
Submitted by: Ali Abdallah <ali.abdallah@suse.com>
MFC after: 2 weeks