firmware: google: memconsole: 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://github.com/KSPP/linux/issues/21

Signed-off-by: Gustavo A. R. Silva <[e-mail]>

drivers/firmware/google/memconsole-coreboot.c

···
 struct cbmem_cons {
 	u32 size_dont_access_after_boot;
 	u32 cursor;
-	u8  body[0];
+	u8  body[];
 } __packed;
 
 #define CURSOR_MASK ((1 << 28) - 1)