NEWS: mention Coverity bug fixes

[Ian Lance Taylor]

msnyder@sonic.net writes:

> + * 37 Coverity issues fixed in bfd, including potential static array 
> +   overruns, null pointer dereferences and use of malloc buffer after 
> +   free.  Coverity generously runs its static analysis suite on the 
> +   GNU tools without charge.

It's nice of Coverity to run these analyses for us, but do we feel OK
about advertising non-free software in a GNU package?

Ian