[SeaBIOS] Coverity detected issues in SeaBIOS

[Kevin O'Connor]

On Wed, Jul 16, 2014 at 04:27:18PM +0100, Ian Campbell wrote:
> Hello,
> 
> We run Coverity on the Xen source code occasionally and it happens to
> include SeaBIOS. The following new warnings have appeared since I pulled
> in rel-1.7.5.

Thanks.  All five look like false positives to me.  I'm happy to take
patches if you want to rework the code to prevent the warnings.

> At least the MISSING_BREAK ones look likely to be valid to me. Not sure
> about the other two...

It's a bit ugly, but it should be okay because all three cases start
with "if (!MODESEGMENT)" which is a compile time constant.  So, when
compiled in 32bit mode the three cases will each return the results
from their respective functions, and in 16bit mode all three will
return DISK_RET_EPARAM.

-Kevin