ksmbd: smbd: fix dma_unmap_sg() nents

ksmbd: smbd: fix dma_unmap_sg() nents

[ Upstream commit 98e3e2b561bc88f4dd218d1c05890672874692f6 ]

The dma_unmap_sg() functions should be called with the same nents as the
dma_map_sg(), not the value the map function returned.

Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
[ Context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>