xfs: move invalidate_kernel_vmap_range to xfs_buf_ioend

Invalidating cache lines can be fairly expensive, so don't do it
in interrupt context.  Note that in practice very few setup will
actually do anything here as virtually indexed caches are rather
uncommon, but we might as well move the call to the proper place
while touching this area.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Acked-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>