nfp: Replace zero-length array with flexible-array member

There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code
should always use "flexible array members"[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: Louis Peens <louis.peens@netronome.com>
Link: https://lore.kernel.org/r/20201204125601.24876-1-simon.horman@netronome.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/netronome/nfp/crypto/fw.h

@@ -40,7 +40,7 @@ struct nfp_crypto_req_add_front {
 	__be16 ipver_vlan __packed;
 	u8 l4_proto;
 #define NFP_NET_TLS_NON_ADDR_KEY_LEN	8
-	u8 l3_addrs[0];
+	u8 l3_addrs[];
 };
 
 struct nfp_crypto_req_add_back {

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c

@@ -1070,7 +1070,7 @@ int nfp_nsp_read_module_eeprom(struct nfp_nsp *state, int eth_index,
 		__le16 offset;
 		__le16 readlen;
 		u8 eth_index;
-		u8 data[0];
+		u8 data[];
 	} __packed *buf;
 	int bufsz, ret;