Added log.isTraceEnabled to LogFileKey (#5499)

There are two trace statements that use Arrays.toString()
as an argument. The methods where these log statements are
found are used frequently in log recovery and the call
to Arrays.toString may be unnecessary if trace logging is
disabled.

Author: dlmarion

server/tserver/src/main/java/org/apache/accumulo/tserver/logger/LogFileKey.java

@@ -293,7 +293,9 @@ private byte[] formatRow(int tabletId, long seq) {
     row[11] = (byte) ((seq >>> 8) & mask);
     row[12] = (byte) (seq & mask);
 
-    log.trace("Convert {} {} {} to row {}", event, tabletId, seq, Arrays.toString(row));
+    if (log.isTraceEnabled()) {
+      log.trace("Convert {} {} {} to row {}", event, tabletId, seq, Arrays.toString(row));
+    }
     return row;
   }
 
@@ -347,8 +349,10 @@ public static LogFileKey fromKey(Key key) {
     if (eventType(logFileKey.event) != rowParts[0]) {
       throw new AssertionError("Event in row differs from column family. Key: " + key);
     }
-    log.trace("From row {} get {} {} {}", Arrays.toString(rowParts), logFileKey.event,
-        logFileKey.tabletId, logFileKey.seq);
+    if (log.isTraceEnabled()) {
+      log.trace("From row {} get {} {} {}", Arrays.toString(rowParts), logFileKey.event,
+          logFileKey.tabletId, logFileKey.seq);
+    }
 
     // handle special cases of what is stored in the qualifier
     switch (logFileKey.event) {