[NO ISSUE][SQL] Fix token name typo in SQL++ parser

- user model changes: no
- storage format changes: no
- interface change: no

Details:
- Fixed token name typo in SQL++ parser

Change-Id: I7288811a6ade385647f58e1b4a2a03b8704f7923
Reviewed-on: https://asterix-gerrit.ics.uci.edu/2136
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Contrib: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Integration-Tests: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>
diff --git a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
index 7c4d15c..a58ce0f 100644
--- a/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
+++ b/asterixdb/asterix-lang-sqlpp/src/main/javacc/SQLPP.jj
@@ -1996,7 +1996,7 @@
         (
             <NULL> { fn = BuiltinFunctions.IS_NULL; } |
             <MISSING> { fn = BuiltinFunctions.IS_MISSING; } |
-            <UNKOWN> { fn = BuiltinFunctions.IS_UNKNOWN; }
+            <UNKNOWN> { fn = BuiltinFunctions.IS_UNKNOWN; }
         )
       {
         FunctionSignature signature = new FunctionSignature(fn);
@@ -3270,7 +3270,7 @@
   | <TYPE : "type">
   | <TO : "to">
   | <UNION : "union">
-  | <UNKOWN : "unknown">
+  | <UNKNOWN : "unknown">
   | <UNNEST : "unnest">
   | <UPDATE : "update">
   | <UPSERT : "upsert">