Passing struct virtchnl_filter f by value requires a 272 byte copy
on x86_64, so instead pass it by reference is much more efficient. Also
adjust some lines that are over 80 chars.

Detected by CoverityScan, CID#1465285 ("Big parameter passed by value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NHarshitha Ramamurthy <harshitha.ramamurthy@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>