Anything under /var needs to be handled by tmpfiles.d. This is a minor change in specfile, otherwise components might have problems logging as seen in some tests:
[73567|mgmtd] sending configuration
[73568|zebra] sending configuration
can't open logfile /var/log/frr/frr-r2.log
line 3: Failure to communicate[13] to mgmtd, line: log file /var/log/frr/frr-r2.log debug

[73574|bgpd] sending configuration
can't open logfile /var/log/frr/frr-r2.log
line 3: Failure to communicate[13] to zebra, line: log file /var/log/frr/frr-r2.log debug

can't open logfile /var/log/frr/frr-r2.log
line 3: Failure to communicate[13] to bgpd, line: log file /var/log/frr/frr-r2.log debug

[73584|staticd] sending configuration
[73568|zebra] Configuration file[/etc/frr/vnc/frr.conf] processing failure: 13
can't open logfile /var/log/frr/frr-r2.log
line 3: Failure to communicate[13] to staticd, line: log file /var/log/frr/frr-r2.log debug
...
Dir /var/log/frr/ needs to be created via the tmpfiles.d.