video: delete unneeded call to platform_get_drvdata

Platform_get_drvdata is an accessor function, and has no purpose if its
result is not used.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/

)

// <smpl>
@@
identifier x;
type T;
@@
- T x = platform_get_drvdata(...);
... when != x
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>