maint: lsb: polish arbitrator's initscript, fix condrestart

• previously, condrestart/try-restart (regardless whether "multi-tenant" or not) would not work as expected
• make it apparent the script is in fact not fully LSB-compliant
• suppress some ShellCheck issues, mostly related to the fact that some variables are injected based on "boothd status" invocation, also drop an unused variable (see commits 8732542 + 054dafa [until which it might have been useful] + 9e6359f)
• fix whitespace issues + normalize indentation of "case - esac"

Signed-off-by: Jan Pokorný <jpokorny@redhat.com>