NFSv4: Add FMODE_CAN_ODIRECT after successful open of a NFS4.x file

NFSv4: Add FMODE_CAN_ODIRECT after successful open of a NFS4.x file

Commit a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag")
added the FMODE_CAN_ODIRECT flag for NFSv3 but neglected to add
it for NFSv4.x.  This causes direct io on NFSv4.x to fail open
with EINVAL:
  mount -o vers=4.2 127.0.0.1:/export /mnt/nfs4
  dd if=/dev/zero of=/mnt/nfs4/file.bin bs=128k count=1 oflag=direct
  dd: failed to open '/mnt/nfs4/file.bin': Invalid argument
  dd of=/dev/null if=/mnt/nfs4/file.bin bs=128k count=1 iflag=direct
  dd: failed to open '/mnt/dir1/file1.bin': Invalid argument

Fixes: a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>