While the old code did support FSCONFIG_SET_FD, there's no need to
re-get the file the fs_context infrastructure already grabbed for us.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Link: https://lore.kernel.org/r/20240731-fsconfig-fsparam_fd-fixes-v2-2-e7c472224417@cyphar.comSigned-off-by: Christian Brauner <brauner@kernel.org>