commit 82163edc upstream.

There is a missing "up_write()" here. Semaphore should be released
before returning error value.
Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>