[media] em28xx: em28xx_urb_data_copy_vbi(): calculate vbi_size only if needed
[media] em28xx: em28xx_urb_data_copy_vbi(): calculate vbi_size only if needed

Signed-off-by: Frank Schäfer <27eadf8cc37a0b12407025a9e98c8c3dd8200904@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas