MDEV-9171: innodb.innodb_uninstall Test Failure

An additional warning saying "tc-log cannot be enabled"
is emitted when InnoDB is installed at runtime on mysqld
built with wsrep-patch (-DWITH_WSREP=ON).

This happens because, installing InnoDB increments the
total number of 2pc-capable engines and with wsrep-patch
already enabled - the total count goes >1. Even though,
this condition is sufficient to enable tc-logging, it is
not permitted at runtime, and thus the warning.

Updated the testcase to avoid the warning.

mysql-test/suite/innodb/r/innodb_uninstall.result

 install plugin innodb soname 'ha_innodb';
-Warnings:
-Warning	1105	Cannot enable tc-log at run-time. XA features of InnoDB are disabled
 create table t1(a int not null primary key) engine=innodb;
 begin;
 insert into t1 values(1);
@@ -12,8 +10,6 @@ sleep(1)
 Warnings:
 Warning	1620	Plugin is busy and will be uninstalled on shutdown
 install plugin innodb soname 'ha_innodb';
-Warnings:
-Warning	1105	Cannot enable tc-log at run-time. XA features of InnoDB are disabled
 drop table t1;
 create table t2(a int not null primary key) engine=innodb;
 insert into t2 values(1);

mysql-test/suite/innodb/t/innodb_uninstall.test

@@ -9,7 +9,13 @@ if (!$HA_INNODB_SO) {
 # MDEV-8474: InnoDB sets per-connection data unsafely
 # Below test caused hang
 #
+# When mysqld is built with wsrep patch (WITH_WSREP=ON),
+# the following install command emits a warning about
+# server unable to enable tc-log at runtime.
+disable_warnings;
 install plugin innodb soname 'ha_innodb';
+enable_warnings;
+
 create table t1(a int not null primary key) engine=innodb;
 
 connect (con1, localhost, root);
@@ -36,7 +42,9 @@ reap;
 
 connect (con1, localhost, root);
 connection con1;
+disable_warnings;
 install plugin innodb soname 'ha_innodb';
+enable_warnings;
 
 drop table t1;
 create table t2(a int not null primary key) engine=innodb;