How to upgrade a single package with ansible?

Is there any specific reason why would you not consider the ansible package module e.g.

- name: Install linux-generic
  package:
    name: linux-generic
    state: present

As far as the ansible error is concerned, you must enclose your command in double quotes since you are using single quotes inside:

 - name: upgrade linux-generic
    when: pkg_chk.rc == 0
      command: "apt-get install -y --only-upgrade -o Dpkg::Options::='force-confdef' -o Dpkg::Options::='force-confold' linux-generic"
      register: install_chk

  - name: autoremove linux-generic
    when: install_chk.rc == 0
      command: "apt-get -y autoremove -o Dpkg::Options::='force-confdef' -o Dpkg::Options::='force-confold'"
      register: auto_chk