common/iobuf.c: Don't abort freeing a pipeline if freeing a filter fails
* common/iobuf.c (iobuf_cancel): Don't abort freeing a pipeline if freeing a filter fails. This needs to a memory leak. Instead, keep freeing and return the error code of the first filter that fails.
- Signed-off-by: Neal H. Walfield <neal@g10code.com>.