NFS: fix eof updates after NFSv4.2 fallocate/zero-range

NFS: fix eof updates after NFSv4.2 fallocate/zero-range

Generic/075 reliably exposes a regression when the client holds an
NFSv4 write delegation: ZERO_RANGE/ALLOCATE extends the file on the
server, but the local inode keeps the old i_size. The test then fails
with 'Size error' because the post-op attribute refresh refuses to
touch i_size while a delegation is outstanding, and the cached EOF
was never marked stale.

Update _nfs42_proc_fallocate() so that on success it:

- bumps i_size when the operation extends the file, and
- marks NFS_INO_INVALID_BLOCKS since the block count can also change

Tested with xfstests generic/075 over NFSv4.2.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>