ctf: fix array dimensions

ctf: fix array dimensions

Due to a premature optimization (in, admittedly, speed-critical code) and
mistakenly forgetting that dwarf_formudata() does not return its result like
dwarf_whatform(), all arrays were considered to be flexible arrays of unknown
dimension.

Also, the type ID representation for arrays was uniquely ugly in that it lacked
a trailing space after the close ].

(Both fixed.)

Signed-off-by: Nick Alcock <nick.alcock@oracle.com>