To display Salesforce as a User License type on report, Below is the workaround:

• Create a Custom Formula Text field under the User object:
  1. Go to Setup | Customize | Users | Fields
  2. Click on New and select “Formula” field type and then “Text”
  3. Use “Profile.UserLicense.Name” in the formula editor
  4. Click on Save
• Create a New Administrative User report:
  1. Go to the Report tab
  2. Click on New report
  3. Under the Administrative reports | Select Users
  4. Add the New Custom Formula field in the report
  5. Run the Report and Save