JBossLogManagerLogger unconditionally does string conversion

JBossLogManagerLogger#doLog always converts the message to a String even if the level isn't loggable. This can have a negative performance impact and result in a lot of unnecessary allocations.

For example LogAuditProvider#audit does trace logging which ends up calling AuditEvent#toString even if trace logging isn't enabled. In our case this results in a lot of allocations outside of TLABs.