In case of several characters present in RxFIFO, they will have the flag of the
previous one, no matter if the actual character was received properly or not.

This patch fixes this bug.
Signed-off-by: NSamuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>