Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8303)
The function B<CRYPTO_free_ex_data> is used to free all exdata attached
to a structure. The appropriate type-specific routine must be used.
The B<class_index> identifies the structure type, the B<obj> is
-be the pointer to the actual structure, and B<r> is a pointer to the
+a pointer to the actual structure, and B<r> is a pointer to the
structure's exdata field.
=head2 Callback Functions