Report 'errno' in int1 field of virErrorPtr

When reporting a system error (VIR_ERR_SYSTEM_ERROR) via
virReportSystemError, we should copy the errno value into
the 'int1' field of the virErrorPtr struct. This allows
callers to detect certain errno conditions & discard the
error

* src/util/virterror.c: Place errno value in int1 field

src/util/virterror.c

@@ -1289,7 +1289,7 @@ void virReportSystemErrorFull(int domcode,
 
     virRaiseErrorFull(filename, funcname, linenr,
                       domcode, VIR_ERR_SYSTEM_ERROR, VIR_ERR_ERROR,
-                      msg, msgDetail, NULL, -1, -1, msg, msgDetail);
+                      msg, msgDetail, NULL, theerrno, -1, msg, msgDetail);
     errno = save_errno;
 }