Introduce virReportError macro for general error reporting

Introduce virReportError macro for general error reporting

Nearly every source file does something like

  #define VIR_FROM_THIS VIR_FROM_FOO
  #define virFooReportErorr(code, ...) \
     virReportErrorHelper(VIR_FROM_THIS, code,  __FILE__,    \
                          __FUNCTION__, __LINE__, \
                          __VA_ARGS__)

This creates needless duplication and inconsistent error
reporting function names in each file. It is trivial to
just have virterror_internal.h provide a virReportError
macro that is equivalent

* src/util/virterror_internal.h: Define virReportError(code, ...)

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>