code style and CHANGES.md fixed

Author: hexudong

CHANGES.md

@@ -14,7 +14,7 @@ Release Notes.
 * Bump up cli to the 0.15.0-dev.latest(77b4c49e89c9c000278f44e62729d534f2ec842e) in e2e.
 * Bump up apache parent pom to v35.
 * Update Maven to 3.6.3 in mvnw.
-* Fix oom due to too many span log.
+* Fix OOM due to too many span logs.
 
 All issues and pull requests are [here](https://github.com/apache/skywalking/milestone/242?closed=1)
 

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java

@@ -175,7 +175,7 @@ public AbstractTracingSpan log(Throwable t) {
         if (!errorOccurred && ServiceManager.INSTANCE.findService(StatusCheckService.class).isError(t)) {
             errorOccurred();
         }
-        if(logs.size() >= Config.Agent.LOG_LIMIT_PER_SPAN){
+        if (logs.size() >= Config.Agent.LOG_LIMIT_PER_SPAN) {
             return this;
         }
         logs.add(new LogDataEntity.Builder().add(new KeyValuePair("event", "error"))
@@ -199,7 +199,7 @@ public AbstractTracingSpan log(long timestampMicroseconds, Map<String, ?> fields
         if (logs == null) {
             logs = new LinkedList<>();
         }
-        if(logs.size() >= Config.Agent.LOG_LIMIT_PER_SPAN){
+        if (logs.size() >= Config.Agent.LOG_LIMIT_PER_SPAN) {
             return this;
         }
         LogDataEntity.Builder builder = new LogDataEntity.Builder();