i40e: Fix of memory leak and integer truncation in i40e_virtchnl.c

Fixed possible memory leak in i40e_vc_add_cloud_filter function:
cfilter is being allocated and in some error conditions
the function returns without freeing the memory.

Fix of integer truncation from u16 (type of queue_id value) to u8
when calling i40e_vc_isvalid_queue_id function.

Signed-off-by: Martyna Szapar <martyna.szapar@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>