Log archiving-related compilation warnings

Seen on release build configurations:

[ 46%] Building CXX object storage/innobase/CMakeFiles/innobase.dir/log/log0log.cc.o
/home/laurynas/percona/lp-mysql-server/percona-server/5.6/storage/innobase/log/log0log.cc: In function ‘ulint log_archive_do(ulint, ulint*)’:
/home/laurynas/percona/lp-mysql-server/percona-server/5.6/storage/innobase/log/log0log.cc:2950:14: warning: ‘limit_lsn’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  ib_uint64_t limit_lsn;
              ^
[ 46%] Building CXX object storage/innobase/CMakeFiles/innobase.dir/srv/srv0start.cc.o
/home/laurynas/percona/lp-mysql-server/percona-server/5.6/storage/innobase/srv/srv0start.cc: In function ‘dberr_t innobase_start_or_create_for_mysql()’:
/home/laurynas/percona/lp-mysql-server/percona-server/5.6/storage/innobase/srv/srv0start.cc:2370:20: warning: ‘min_arch_log_no’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    min_arch_log_no);
                    ^