dma-buf-map: Fix-up iosys-map integration

commit 43f948eba705c954cb8f352099426b6137d780ba from
https://nv-tegra.nvidia.com/r/3rdparty/canonical/linux-jammy.git jetson_36.3

BugLink: https://bugs.launchpad.net/bugs/2034622

When integrating upstream commit 7938f421 ("dma-buf-map: Rename to
iosys-map") an addition declaration of the 'src' variable was introduced
into the DRM MIPI DBI driver causing the build to fail. Fix this by
removing this additional declaration.

http://nvbugs/4262148



Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Brad Griffis <bgriffis@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jacob Martin <jacob.martin@canonical.com>
Acked-by: Noah Wager <noah.wager@canonical.com>
Signed-off-by: Jacob Martin <jacob.martin@canonical.com>
Signed-off-by: Rajeshkumar Ramasamy <rajeshkumar.ramasamy@windriver.com>