V4L/DVB (6102): dvb: remove some unneeded vmalloc() return value casts from av7110

vmalloc() returns void * - no need to cast it.

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>