media: em28xx: Don't use ops->resume if NULL

media: em28xx: Don't use ops->resume if NULL

Changeset  be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD
second tuner functionality") introduced a potential NULL pointer
dereference, as pointed by Coverity:

CID 1434731 (#1 of 1): Dereference after null check (FORWARD_NULL)16. var_deref_op: Dereferencing null pointer ops->resume.

var_compare_op: Comparing ops->resume to null implies that ops->resume might be null.
1174                if (ops->resume)
1175                        ops->resume(dev);
1176                if (dev->dev_next)
1177                        ops->resume(dev->dev_next);

Fixes: be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD second tuner functionality")

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>