CVE-2013-2230

Don't overwrite the callback ID returned by
virDomainEventStateRegisterID in ret by 0.

Introduced by abf75aea.

Remove assignment of the string freed by virURIFree
to hostname, since it's not used anywhere.

Double free introduced by ddf8ad82, useless code
introduced by f03dcc5d.

https://bugzilla.redhat.com/show_bug.cgi?id=977961

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Actually, I'm turning this function into a macro as filename,
function name and line number needs to be passed. The new
function virAsprintfInternal is introduced with the extended set
of arguments.

Similarly to VIR_STRDUP, we want the OOM error to be reported in
VIR_ALLOC and friends.