Fixed compiler warnings

client/readline.cc:
  Fixed compiler warning
mysql-test/suite/innodb/t/innodb_bug60049.test:
  This test failed when running with --mysqld=--loose-innodb-fast-shutdown=2 which we do on some machines
mysql-test/t/mysqldump.test:
  Only run test if utf8 is used
sql/log.cc:
  Fixed compiler warning
sql/mysql_priv.h:
  Fixed compiler warnings
tests/mysql_client_test.c:
  Don't abort test if ucs2 is not in use.