Fix type name

Author: ThomsonTan

exporters/user_events/include/opentelemetry/exporters/user_events/logs/recordable.h

@@ -124,7 +124,7 @@ class Recordable final : public opentelemetry::sdk::logs::Recordable
   size_t cs_part_b_bookmark_size_ = 0;
   size_t cs_part_c_bookmark_      = 0;
   size_t cs_part_c_bookmark_size_ = 0;
-  uint_8 severity_                = 0; 
+  uint8_t severity_               = 0;
   bool has_event_id_              = false;
 };