Reset user status after unix_socket.test

Fixed mysql-test-run failures for roles.acl_statistics

mysql-test/suite/plugins/r/unix_socket.result

@@ -27,4 +27,5 @@ USER@localhost	@%	test
 # name does not match = failure
 #
 delete from mysql.user where user='';
+FLUSH PRIVILEGES;
 uninstall plugin unix_socket;

mysql-test/suite/plugins/t/unix_socket.test

@@ -55,6 +55,6 @@ grant SELECT ON test.* TO '' identified via unix_socket;
 
 # restoring mysql.user to the original state.
 delete from mysql.user where user='';
+FLUSH PRIVILEGES;
 uninstall plugin unix_socket;
 --remove_file $MYSQLTEST_VARDIR/tmp/peercred_test.txt
-