Fix Bug #55027: assertion: mutex_own(&dict_sys->mutex) in dict_table_get_on_id()

The callers should indicate that the dictionary is locked or not using
the trx->dict_operation_lock_mode == RW_X_LATCH mode. Checking explicitly
for system tables is unnecessary.

Approved by Marko on IRC.

storage/innobase/dict/dict0dict.c

@@ -616,8 +616,7 @@ dict_table_get_on_id(
 {
 	dict_table_t*	table;
 
-	if (ut_dulint_cmp(table_id, DICT_FIELDS_ID) <= 0
-	    || trx->dict_operation_lock_mode == RW_X_LATCH) {
+	if (trx->dict_operation_lock_mode == RW_X_LATCH) {
 
 		/* Note: An X latch implies that the transaction
 		already owns the dictionary mutex. */

storage/innodb_plugin/dict/dict0dict.c

@@ -568,8 +568,7 @@ dict_table_get_on_id(
 {
 	dict_table_t*	table;
 
-	if (ut_dulint_cmp(table_id, DICT_FIELDS_ID) <= 0
-	    || trx->dict_operation_lock_mode == RW_X_LATCH) {
+	if (trx->dict_operation_lock_mode == RW_X_LATCH) {
 
 		/* Note: An X latch implies that the transaction
 		already owns the dictionary mutex. */