media: pwc: 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/21Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

drivers/media/usb/pwc/pwc.h

@@ -193,7 +193,7 @@ struct pwc_raw_frame {
 				   decompressor) */
 	__u8   cmd[4];		/* the four byte of the command (in case of
 				   nala, only the first 3 bytes is filled) */
-	__u8   rawframe[0];	/* frame_size = H / 4 * vbandlength */
+	__u8   rawframe[];	/* frame_size = H / 4 * vbandlength */
 } __packed;
 
 /* intermediate buffers with raw data from the USB cam */