libctf: don't leak the symbol name in the name->type cache

This cache replaced a cache of symbol index->ctf_id_t. That cache was
just an array, so it could get away with just being free()d, but the
ctfi_symnamedicts cache that replaced it is a full dynhash with a
dynamically-allocated string as the key.  As such, it needs freeing with
ctf_dynhash_destroy(), not just free(), or we leak parts of the
underlying hashtab, and all the keys.

libctf/ChangeLog:

	* ctf-archive.c (ctf_arc_flush_caches): Fix leak.

libctf/ctf-archive.c

@@ -699,7 +699,7 @@ void
 ctf_arc_flush_caches (ctf_archive_t *wrapper)
 {
   free (wrapper->ctfi_symdicts);
-  free (wrapper->ctfi_symnamedicts);
+  ctf_dynhash_destroy (wrapper->ctfi_symnamedicts);
   ctf_dynhash_destroy (wrapper->ctfi_dicts);
   wrapper->ctfi_symdicts = NULL;
   wrapper->ctfi_symnamedicts = NULL;