E: Malformed entry 54 in list file /etc/apt/sources.list (Component)
You have not provided the release codename.
For example, for Ubuntu 14.04 (trusty):
deb http://archive.canonical.com/ubuntu trusty partner
Replace trusty with the codename of the release you are using.
As you are using 16.04 (xenial):
deb http://archive.canonical.com/ubuntu xenial partner
You can find out the release codename by:
lsb_release -c
Just the release codename:
lsb_release -sc