HBASE-21322 Add a scheduleServerCrashProcedure() API to HbckService (addendum for branch-2)

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegionServer.java

@@ -2880,7 +2880,7 @@ public class HRegionServer extends HasThread implements
   /**
    * @return Return the walRootDir.
    */
-  protected Path getWALRootDir() {
+  public Path getWALRootDir() {
     return walRootDir;
   }