NFS: Ensure the server has an up to date ctime before renaming

NFS: Ensure the server has an up to date ctime before renaming

BugLink: https://bugs.launchpad.net/bugs/1959879
[ Upstream commit 6ff9d99bb88faebf134ca668842349d9718e5464 ]

Renaming a file is required by POSIX to update the file ctime, so
ensure that the file data is synced to disk so that we don't clobber the
updated ctime by writing back after creating the hard link.

Fixes: f2c2c552f119 ("NFS: Move delegation recall into the NFSv4 callback for rename_setup()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>