MFC r220299:

In g_eli_read_done() and g_eli_write_done(), for a bio with
bio_children > 1, g_destroy_bio() is never called and the bio
leaks. Fix this by calling g_destroy_bio() earlier, before the check.

Submitted by: Victor Balada Diaz <victor@bsdes.net> (initial version)

Tested by: Oliver Pinter <oliver.pinter@gmail.com>
Approved by: kib (co-mentor)