libipt: remove pdf_status_have_ip

The pdf_status_have_ip decoder flag is not used any more.  Remove it.

Change-Id: I45049f5d01ee25ef32c1c0a39c92fc65a7952a7d
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
libipt: start with tracing disabled

When initializing or resetting the decoder, start with tracing disabled.  It
will be set to enabled if we find a FUP in the PSB+ header after synchronizing
onto the trace stream.

Change-Id: I801a65a8c15382a390896ab8cb6f6c176d0945ea
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>