ice: fix using untrusted value of pkt_len in ice_vc_fdir_parse_raw()

Fix using the untrusted value of proto->raw.pkt_len in function
ice_vc_fdir_parse_raw() by verifying if it does not exceed the
VIRTCHNL_MAX_SIZE_RAW_PACKET value.

Fixes: 99f419df ("ice: enable FDIR filters from raw binary patterns for VFs")
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Mateusz Polchlopek <mateusz.polchlopek@intel.com>
Signed-off-by: Martyna Szapar-Mudlaw <martyna.szapar-mudlaw@linux.intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>