Remove GroupCommitService#run synchronized code chunk

[mxsm]

GroupCommitService#swapRequests has used lock

rocketmq/store/src/main/java/org/apache/rocketmq/store/CommitLog.java

Lines 1461 to 1470 in f8bf7bd

	private void swapRequests() {
	lock.lock();
	try {
	LinkedList<GroupCommitRequest> tmp = this.requestsWrite;
	this.requestsWrite = this.requestsRead;
	this.requestsRead = tmp;
	} finally {
	lock.unlock();
	}
	}

this code chunk used synchronized

rocketmq/store/src/main/java/org/apache/rocketmq/store/CommitLog.java

Lines 1519 to 1521 in f8bf7bd

	synchronized (this) {
	this.swapRequests();
	}

synchronized can be removed