Enable readability-implicit-bool-conversion checks

These checks ensure that we're not implicitly converting ints or
pointers into bools, which makes the code easier to read.

Tested:
Ran series through redfish service validator.  No changes observed.
UUID failing in Qemu both before and after.

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I1ca0be980d136bd4e5474341f4fd62f2f6bbdbae
diff --git a/include/dbus_monitor.hpp b/include/dbus_monitor.hpp
index 9bc79ad..8519b5a 100644
--- a/include/dbus_monitor.hpp
+++ b/include/dbus_monitor.hpp
@@ -31,7 +31,7 @@
 inline int onPropertyUpdate(sd_bus_message* m, void* userdata,
                             sd_bus_error* retError)
 {
-    if (retError == nullptr || sd_bus_error_is_set(retError))
+    if (retError == nullptr || (sd_bus_error_is_set(retError) != 0))
     {
         BMCWEB_LOG_ERROR << "Got sdbus error on match";
         return 0;