branch-3.0: [opt](jni) Modify Exception Cause Formatting in JniUtil f…

…or Better Readability apache#46437 (apache#46601)

Cherry-picked from apache#46437

Co-authored-by: zy-kkk <zhongyk10@gmail.com>

fe/be-java-extensions/java-common/src/main/java/org/apache/doris/common/jni/utils/JniUtil.java

@@ -72,7 +72,7 @@ public static String throwableToString(Throwable t) {
         // Follow the chain of exception causes and print them as well.
         Throwable cause = t;
         while ((cause = cause.getCause()) != null) {
-            output.write(String.format("\nCAUSED BY: %s: %s",
+            output.write(String.format(" | CAUSED BY: %s: %s",
                     cause.getClass().getSimpleName(), cause.getMessage()));
         }
         return output.toString();