sdk: set correct span limit in builder (#2405)

Author: djc

opentelemetry-sdk/src/trace/provider.rs

@@ -336,7 +336,7 @@ impl Builder {
 
     /// Specify the number of events to be recorded per span.
     pub fn with_max_events_per_span(mut self, max_events: u32) -> Self {
-        self.config.span_limits.max_attributes_per_span = max_events;
+        self.config.span_limits.max_events_per_span = max_events;
         self
     }