How do I exit MySQL safe mode?

CTRL + Z will suspend mysqld_safe process, which can be revival by fg command. For killing the mysqld_safe you need to run mysqladmin -u root -p shutdown in another terminal or after hold CTRL + Z

Firstly, your last command didn't end, so type ; to end the current command. Then you can continue, including the following to exit mysql altogether.

Simply use the following command/keys.