media: s5p_mfc: fix doublly free issue

media: s5p_mfc: fix doublly free issue

When video_register_device() returns failure, vfd will be freed at once and
dev->vfl_dec will be freed after label "err_dec_reg", but the two pointers point
to the same area, so it was doublly freed here. Since video_device_release()
will be called by video_unregister_device() indirectly, we should remove the
two other calls after labels err_enc_reg and err_dec_reg.

Change-Id: I5ee8f83eeb47443e2f772914127514eab996c347
Signed-off-by: Zhaowei Yuan <zhaowei.yuan@samsung.com>