It is possible that mtk_vcodec_enc_pw_on fails, and in that scenario
the PM counter is not incremented, and subsequent call to
mtk_vcodec_enc_pw_off decrements the counter, leading to a PM imbalance.
Fix by bailing out of venc_if_encode in the case when mtk_vcodec_enc_pw_on
fails.
Fixes: 4e855a6efa54 ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")
Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>