[S390] qdio: EQBS retry after CCQ 96

Running under z/VM with QIOASSIST enabled, qdio queues could stall if EQBS
did not extract all SBAL states. Add an instant retry for EQBS and, if the
retry fails, set up a timer to ensure outstanding SBALs are processed later.

While at it, optimize qdio_do_eqbs and qdio_do_sqbs to eliminate 3 jumps on
the hot path.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>