[mythtv] status of MythTV wrt Coverity Scan

[Preston Crow]

In my experience with Coverity, while many of the defects will be false 
positives, most of the time changing the code to avoid the false 
positive results in cleaner code.  I've also seen lots of developers 
flag defects as false positives only to go back later and fix them 
because it turned out that Coverity was right.  As a general rule, I now 
either change the code, or add a comment on the line in question 
explaining why Coverity isn't happy.