media: pci: cx23885: replace BUG with error return

stable inclusion
from stable-v5.10.197
commit 890d10e6b72fc7e51bcb261679e1117f3520ca97
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I96Q8P

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=890d10e6b72fc7e51bcb261679e1117f3520ca97



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[ Upstream commit 2e1796fd ]

It was completely unnecessary to use BUG in buffer_prepare().
Just replace it with an error return. This also fixes a smatch warning:

drivers/media/pci/cx23885/cx23885-video.c:422 buffer_prepare() error: uninitialized symbol 'ret'.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>