samples: mei: Replace zero-length array with flexible-array

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://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

samples/mei/mei-amt-version.c

@@ -267,7 +267,7 @@ struct amt_host_if_msg_header {
 struct amt_host_if_resp_header {
 	struct amt_host_if_msg_header header;
 	uint32_t status;
-	unsigned char data[0];
+	unsigned char data[];
 } __attribute__((packed));
 
 const uuid_le MEI_IAMTHIF = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,  \