[SPARK-15108][SQL] Describe Permanent UDTF

#### What changes were proposed in this pull request?
When Describe a UDTF, the command returns a wrong result. The command is unable to find the function, which has been created and cataloged in the catalog but not in the functionRegistry.

This PR is to correct it. If the function is not in the functionRegistry, we will check the catalog for collecting the information of the UDTF function.

#### How was this patch tested?
Added test cases to verify the results

Author: gatorsmile <gatorsmile@gmail.com>

Closes #12885 from gatorsmile/showFunction.

1 files changed, 2 insertions, 2 deletions

diff --git a/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/HiveThriftServer2Suites.scala b/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/HiveThriftServer2Suites.scala
index 1a894ae857..b3f4944c91 100644
--- a/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/HiveThriftServer2Suites.scala
+++ b/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/HiveThriftServer2Suites.scala
@@ -534,7 +534,7 @@ class HiveThriftHttpServerSuite extends HiveThriftJdbcTest {
         }
 
         assert(rs1.next())
-        assert(rs1.getString(1) === "Usage: To be added.")
+        assert(rs1.getString(1) === "Usage: N/A.")
 
         val dataPath = "../hive/src/test/resources/data/files/kv1.txt"
 
@@ -608,7 +608,7 @@ class SingleSessionSuite extends HiveThriftJdbcTest {
           }
 
           assert(rs2.next())
-          assert(rs2.getString(1) === "Usage: To be added.")
+          assert(rs2.getString(1) === "Usage: N/A.")
         } finally {
           statement.executeQuery("DROP TEMPORARY FUNCTION udtf_count2")
         }