usb: isp1760-hcd: Fix fall-through annotations

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Wed, May 01, 2019 at 10:39:34AM -0500, Gustavo A. R. Silva wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch
> cases where we are expecting to fall through.
> 
> This patch fixes the following warning:
> 
> drivers/usb/isp1760/isp1760-hcd.c: In function ‘collect_qtds’:
> drivers/usb/isp1760/isp1760-hcd.c:788:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
>       mem_reads8(hcd->regs, qtd->payload_addr,
>       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>         qtd->data_buffer,
>         ~~~~~~~~~~~~~~~~~
>         qtd->actual_length);
>         ~~~~~~~~~~~~~~~~~~~
> drivers/usb/isp1760/isp1760-hcd.c:792:5: note: here
>      case OUT_PID:
>      ^~~~
> 
> Warning level 3 was used: -Wimplicit-fallthrough=3
> 
> Notice that, in this particular case, the code comments are modified
> in accordance with what GCC is expecting to find.
> 
> This patch is part of the ongoing efforts to enable
> -Wimplicit-fallthrough.
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
> ---
> Notice that this code has been out there since 2011, and who
> introduced the question mark was the original developer.
> 
> It'd be good if someone can confirm that the fall-through
> has been intentional all this time.

Yes, it looks intentional.  Messy, and as no one has complained since
2011, let's leave it alone, I'll queue this up.

thanks,

greg k-h