dw2102: some missing unlocks on error

commit 324ed533bf0b23c309b805272c4ffcc5d51493a6 upstream.

We recently introduced some new error paths but the unlocks are missing.
Fixes: 0065a79a8698 ('[media] dw2102: Don't use dynamic static allocation')

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
[bwh: Backported to 3.2: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>