ecpg: Fix typo

GCC 6 points out the redundant conditions, which were apparently typos.
Reviewed-by: Thomas Munro <thomas.munro@enterprisedb.com>

src/interfaces/ecpg/test/compat_informix/describe.pgc

@@ -150,7 +150,7 @@ exec sql end declare section;
 	exec sql describe st_id2 using descriptor sqlda2;
 	exec sql describe st_id2 into sqlda3;
 
-	if (sqlda1 == NULL || sqlda1 == NULL || sqlda2 == NULL)
+	if (sqlda1 == NULL || sqlda2 == NULL || sqlda3 == NULL)
 		exit(1);
 
 	strcpy(msg, "get descriptor");

src/interfaces/ecpg/test/expected/compat_informix-describe.c

@@ -362,7 +362,7 @@ if (sqlca.sqlcode < 0) exit (1);}
 #line 151 "describe.pgc"
 
 
-	if (sqlda1 == NULL || sqlda1 == NULL || sqlda2 == NULL)
+	if (sqlda1 == NULL || sqlda2 == NULL || sqlda3 == NULL)
 		exit(1);
 
 	strcpy(msg, "get descriptor");

src/interfaces/ecpg/test/expected/sql-describe.c

@@ -360,7 +360,7 @@ if (sqlca.sqlcode < 0) exit (1);}
 #line 151 "describe.pgc"
 
 
-	if (sqlda1 == NULL || sqlda1 == NULL || sqlda2 == NULL)
+	if (sqlda1 == NULL || sqlda2 == NULL || sqlda3 == NULL)
 		exit(1);
 
 	strcpy(msg, "get descriptor");

src/interfaces/ecpg/test/sql/describe.pgc

@@ -150,7 +150,7 @@ exec sql end declare section;
 	exec sql describe st_id2 using descriptor sqlda2;
 	exec sql describe st_id2 into sqlda3;
 
-	if (sqlda1 == NULL || sqlda1 == NULL || sqlda2 == NULL)
+	if (sqlda1 == NULL || sqlda2 == NULL || sqlda3 == NULL)
 		exit(1);
 
 	strcpy(msg, "get descriptor");