Fix lowpkg.diff documentation and parameter name
Fix lowpkg.diff documentation and parameter name

Package names are useless for lowpkg.diff, as to make a full
comparison we need to access the RPM

Fix #50097

(cherry picked from commit 5484791c0f953de2c2e6c5c65c3621b67e3b0f5d)

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt