chore(debugging): correct probe injection logging (#5895)

The logic for the debug logging of injected probes was incorrect and
could have caused the same log message to be emitted multiple times. In
other cases the information emitted would have resulted inaccurate,
particularly when a line probe failed to inject.

Author: P403n1x87

ddtrace/debugging/_debugger.py

@@ -443,19 +443,23 @@ def _probe_injection_hook(self, module):
             failed = self._function_store.inject_hooks(
                 function, [(self._dd_debugger_hook, cast(LineProbe, probe).line, probe) for probe in probes]
             )
+
             for probe in probes:
                 if probe.probe_id in failed:
                     self._probe_registry.set_error(probe, "Failed to inject")
-                    log.error("[%s][P: %s] Failed to inject %r", os.getpid(), os.getppid(), probe)
                 else:
                     self._probe_registry.set_installed(probe)
-                    log.debug(
-                        "[%s][P: %s] Injected probes %r in %r",
-                        os.getpid(),
-                        os.getppid(),
-                        [probe.probe_id for probe in probes],
-                        function,
-                    )
+
+            if failed:
+                log.error("[%s][P: %s] Failed to inject probes %r", os.getpid(), os.getppid(), failed)
+
+            log.debug(
+                "[%s][P: %s] Injected probes %r in %r",
+                os.getpid(),
+                os.getppid(),
+                [probe.probe_id for probe in probes if probe.probe_id not in failed],
+                function,
+            )
 
     def _inject_probes(self, probes):
         # type: (List[LineProbe]) -> None