i40e: Replace one-element array with flex-array member in struct i40e_package_header

One-element and zero-length arrays are deprecated. So, replace
one-element array in struct i40e_package_header with flexible-array
member.

The `+ sizeof(u32)` adjustments ensure that there are no differences
in binary output.

Link: https://github.com/KSPP/linux/issues/335Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/i40e/i40e_ddp.c

@@ -220,7 +220,7 @@ static bool i40e_ddp_is_pkg_hdr_valid(struct net_device *netdev,
 		netdev_err(netdev, "Invalid DDP profile - size is bigger than 4G");
 		return false;
 	}
-	if (size < (sizeof(struct i40e_package_header) +
+	if (size < (sizeof(struct i40e_package_header) + sizeof(u32) +
 		sizeof(struct i40e_metadata_segment) + sizeof(u32) * 2)) {
 		netdev_err(netdev, "Invalid DDP profile - size is too small.");
 		return false;
@@ -281,7 +281,7 @@ int i40e_ddp_load(struct net_device *netdev, const u8 *data, size_t size,
 	if (!i40e_ddp_is_pkg_hdr_valid(netdev, pkg_hdr, size))
 		return -EINVAL;
 
-	if (size < (sizeof(struct i40e_package_header) +
+	if (size < (sizeof(struct i40e_package_header) + sizeof(u32) +
 		    sizeof(struct i40e_metadata_segment) + sizeof(u32) * 2)) {
 		netdev_err(netdev, "Invalid DDP recipe size.");
 		return -EINVAL;

drivers/net/ethernet/intel/i40e/i40e_type.h

@@ -1455,7 +1455,7 @@ struct i40e_ddp_version {
 struct i40e_package_header {
 	struct i40e_ddp_version version;
 	u32 segment_count;
-	u32 segment_offset[1];
+	u32 segment_offset[];
 };
 
 /* Generic segment header */