MDEV-8855: innodb.innodb-fk-warnings fails on Windows

Fixed incorrect access to freed memory.

Author: Jan Lindström

storage/innobase/dict/dict0dict.c

@@ -4225,7 +4225,6 @@ dict_create_foreign_constraints_low(
 	ptr = dict_accept(cs, ptr, ")", &success);
 
 	if (!success || foreign->n_fields != i) {
-		dict_foreign_free(foreign);
 
 		dict_foreign_report_syntax_err(
 			"%s table %s with foreign key constraint"
@@ -4238,6 +4237,9 @@ dict_create_foreign_constraints_low(
 			" failed. Foreign key constraint parse error in %s"
 			" close to %s. Too few referenced columns, you have %d when you should have %d.",
 			operation, create_name, start_of_latest_foreign, orig, i, foreign->n_fields);
+
+		dict_foreign_free(foreign);
+
 		return(DB_CANNOT_ADD_CONSTRAINT);
 	}
 

storage/xtradb/dict/dict0dict.c

@@ -4357,7 +4357,6 @@ dict_create_foreign_constraints_low(
 	ptr = dict_accept(cs, ptr, ")", &success);
 
 	if (!success || foreign->n_fields != i) {
-		dict_foreign_free(foreign);
 
 		dict_foreign_report_syntax_err(
 			"%s table %s with foreign key constraint"
@@ -4370,6 +4369,9 @@ dict_create_foreign_constraints_low(
 			" failed. Foreign key constraint parse error in %s"
 			" close to %s. Too few referenced columns, you have %d when you should have %d.",
 			operation, create_name, start_of_latest_foreign, orig, i, foreign->n_fields);
+
+		dict_foreign_free(foreign);
+
 		return(DB_CANNOT_ADD_CONSTRAINT);
 	}