[S390] qdio: re-add lost perf_stats.tl_runs change in qdio_handle_pci

Statement has been inadvertently lost with commit
00c0c646

.

Signed-off-by: Ursula Braun <braunu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>