[MySQL]: “Access denied for user ‘debian-sys-maint’@’localhost’”

#
# sudo cat /etc/mysql/debian.cnf
#

# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host     = localhost
user     = debian-sys-maint
password = 비밀번호
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
user     = debian-sys-maint
password = 비밀번호
socket   = /var/run/mysqld/mysqld.sock
basedir  = /usr

#mysql -u root -p <password>

mysql> GRANT ALL PRIVILEGES ON *.* TO 'debian-sys-maint'@'localhost' IDENTIFIED BY '비밀번호';

#sudo /etc/init.d/mysql restart