MDEV-18214 cleanup: Remove redundant MONITOR_INC calls

MONITOR_PENDING_CHECKPOINT_WRITE and MONITOR_LOG_IO track
log_sys.n_pending_checkpoint_writes and log_sys.n_log_ios,
respectively. The MONITOR_INC calls are redundant, because
the values will be overwritten in srv_mon_process_existing_counter().

storage/innobase/log/log0log.cc

@@ -1373,12 +1373,8 @@ void log_write_checkpoint_info(lsn_t end_lsn)
 
 	log_block_store_checksum(buf);
 
-	MONITOR_INC(MONITOR_PENDING_CHECKPOINT_WRITE);
-
 	log_sys.n_log_ios++;
 
-	MONITOR_INC(MONITOR_LOG_IO);
-
 	ut_ad(LOG_CHECKPOINT_1 < srv_page_size);
 	ut_ad(LOG_CHECKPOINT_2 < srv_page_size);
 

storage/innobase/log/log0recv.cc

@@ -1183,8 +1183,6 @@ bool log_t::file::read_log_seg(lsn_t* start_lsn, lsn_t end_lsn)
 
 	log_sys.n_log_ios++;
 
-	MONITOR_INC(MONITOR_LOG_IO);
-
 	ut_a((source_offset >> srv_page_size_shift) <= ULINT_MAX);
 
 	recv_sys.read(source_offset, {buf, len});