Fix typo in regression test comment

per Michael Banck

src/test/regress/expected/fast_default.out

@@ -728,7 +728,7 @@ SELECT * FROM t;
 
 DROP TABLE t;
 -- make sure expanded tuple has correct self pointer
--- it will be required by the RI tigger doing the cascading delete
+-- it will be required by the RI trigger doing the cascading delete
 CREATE TABLE leader (a int PRIMARY KEY, b int);
 CREATE TABLE follower (a int REFERENCES leader ON DELETE CASCADE, b int);
 INSERT INTO leader VALUES (1, 1), (2, 2);

src/test/regress/sql/fast_default.sql

@@ -472,7 +472,7 @@ SELECT * FROM t;
 DROP TABLE t;
 
 -- make sure expanded tuple has correct self pointer
--- it will be required by the RI tigger doing the cascading delete
+-- it will be required by the RI trigger doing the cascading delete
 
 CREATE TABLE leader (a int PRIMARY KEY, b int);
 CREATE TABLE follower (a int REFERENCES leader ON DELETE CASCADE, b int);