USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL

USB: cdc-acm: fix close_delay and closing_wait units in TIOCSSERIAL

commit 38d33f51beaf2891561b5e765ae1445662de4d63 upstream.

close_delay and closing_wait are specified in hundredth of a second but stored
internally in jiffies. Use the jiffies_to_msecs() and msecs_to_jiffies()
functions to convert from each other.

Signed-off-by: Anthony Mallet <anthony.mallet@laas.fr>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200312133101.7096-1-anthony.mallet@laas.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>