n_tty: Simplify throttle threshold calculation

The adjustments performed by receive_room() are to ensure a line
termination can always be written to the read buffer. However,
these adjustments are irrelevant to the throttle threshold (because
the threshold < buffer limit).

Signed-off-by: Peter Hurley <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
1 file changed