perf intel-pt: Packet splitting can happen only on 32-bit

perf intel-pt: Packet splitting can happen only on 32-bit

Data is copied when the trace is stopped, so packets are never split
between buffers except when processing if the buffer cannot fit in the
address space which can only happen on 32-bit systems. Change the logic
to reflect that.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20190206103947.15750-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>