common/iobuf.c: Fix filter type for iobuf_temp_with_content.
* common/iobuf.c (iobuf_temp_with_content): Set the filter type to IOBUF_INPUT, not IOBUF_TEMP, which is only for output filters that write into a dynamic buffer.
- Signed-off-by: Neal H. Walfield <neal@g10code.com>.