[media] saa7164-dvb: Remove unnecessary null test

[media] saa7164-dvb: Remove unnecessary null test

This patch removes the null test on dvb. dvb is initialized at the
beginning of the function to &port->dvb. Since port is dereferenced
prior to the null test, port must be a valid pointer, and
&port->dvb cannot be null.

The following Coccinelle script is used for detecting the change:

@r@
expression e,f;
identifier g,y;
statement S1,S2;
@@

*e = &f->g
<+...
 f->y
 ...+>
*if (e != NULL || ...)
 S1 else S2

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>