xfs: remove spurious shutdown type check from xfs_bmap_finish()

The static checker reports that after commit 8d99fe92 ("xfs: fix
efi/efd error handling to avoid fs shutdown hangs"), the code has been
reworked such that error == -EFSCORRUPTED is not possible in this
codepath.

Remove the spurious error check and just use SHUTDOWN_META_IO_ERROR
unconditionally.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>