FROMGIT: dma-buf: acquire name lock before read/write dma_buf.name

Because dma-buf.name can be freed in func: "dma_buf_set_name",
so, we need to acquire lock first before we read/write dma_buf.name
to prevent Use After Free(UAF) issue.

Signed-off-by: Guangming Cao <Guangming.Cao@mediatek.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/lkml/20211029021541.101157-1-guangming.cao@mediatek.com/T/

Bug: 205102180
(cherry picked from commit 8c0fd126
 https://cgit.freedesktop.org/drm/drm-misc

)
Change-Id: I4ba911137ad9dae7682230245d2fa2a19f7c209f
Signed-off-by: Yunfei Wang <yf.wang@mediatek.com>