rectify comment/explanation on inner middleware for exception handling

Author: outergod

instrumentation/opentelemetry-instrumentation-fastapi/src/opentelemetry/instrumentation/fastapi/__init__.py

@@ -330,9 +330,8 @@ def build_middleware_stack(self: Starlette) -> ASGIApp:
             # Define an additional middleware for exception handling that gets
             # added as a regular user middleware.
             # Normally, `opentelemetry.trace.use_span` covers the recording of
-            # exceptions into the active span, but because of order of
-            # middleware execution, that doesn't work so we have to do it in an
-            # inner middleware.
+            # exceptions into the active span, but `OpenTelemetryMiddleware`
+            # ends the span too early before the excepetion can be recorded.
             class ExceptionHandlerMiddleware:
                 def __init__(self, app):
                     self.app = app