Btrfs: return the internal error unchanged if btrfs_get_extent_fiemap() call failed...

Given that ENXIO only means "offset beyond EOF" for either SEEK_DATA or SEEK_HOLE inquiry
in a desired file range, so we should return the internal error unchanged if btrfs_get_extent_fiemap()
call failed, rather than ENXIO.

Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jie Liu <jeff.liu@oracle.com>

diff --cc fs/btrfs/file.c
Simple merge