QMP: Drop dead code

QMP: Drop dead code

The first if/else clause in handler_audit() makes no sense for two
reasons:

  1. this function is now called only by QMP code, so testing if
     it's a QMP call makes no sense anymore

  2. the else clause first asserts that there's no error in the
     monitor object, then it tries to free it!

Just drop it.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>