commit f37f29d31488 "xen: slightly simplify bufioreq handling" hard
coded setting req.count = 1 during initial field setup before the main
loop. This missed a subtlety that an early exit from the loop when
there are no ioreqs to process, would have req.count == 0 for the return
value. handle_buffered_io() would then remove state->buffered_io_timer.
Instead handle_buffered_iopage() is basically always returning true and
handle_buffered_io() always re-setting the timer.
Restore the disabling of the timer by introducing a new handled_ioreq
boolean and use as the return value. The named variable will more
clearly show the intent of the code.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>