media: dvb-frontends: fix leak of memory fw

[ Upstream commit a15fe8d9f1bf460a804bcf18a890bfd2cf0d5caa ]

Link: https://lore.kernel.org/linux-media/20220410061925.4107-1-chinayanlei2002@163.com


Signed-off-by: Yan Lei <yan_lei@dahuatech.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>