capsicum_helpers: Add FIODTYPE to default ioctls allowed

[kevans]

Summary

hexdump(1) will soon use FIODTYPE to determine if it's reading a tape drive,
and it seems to be a harmless enough addition.

[cem]

Wait, why does hexdump need to know if it's reading from a tape device?

[kevans]

In D10937#226483, @cem wrote:

Wait, why does hexdump need to know if it's reading from a tape device?

See: D10939 (just created) -- I've no idea if it's still the case, but arundel@ suggested (in 2011, mind) that most tape devices don't support seeking yet fseek succeeds, so it checks this to workaround that behavior and properly seek through a tape device. I don't know enough about tape devices to tell if this is still the case, but hexdump doesn't fail miserably with tape devices post-D10939, it just treats them as regular files.

[kevans]

Sorry, careless wording -- not treated as a regular file, but as a non-fseekable one. =)

[cem]

Seems harmless to allow in the sandbox.