xfs: remove some EXPERIMENTAL warnings

Online fsck was finished a year ago, in Linux 6.10.  The exchange-range
syscall and parent pointers were merged in the same cycle.  None of
these have encountered any serious errors in the year that they've been
in the kernel (or the many many years they've been under development) so
let's drop the shouty warnings.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>