[#1085] log: Move storage log message to constants package

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

internal/logs/logs.go

@@ -201,6 +201,7 @@ const (
 	SubscriberCantCastBlockEventValueToBlock                                = "can't cast block event value to block"
 	SubscriberCantCastNotifyEventValueToTheNotaryRequestStruct              = "can't cast notify event value to the notary request struct"
 	SubscriberUnsupportedNotificationFromTheChain                           = "unsupported notification from the chain"
+	StorageOperation                                                        = "local object storage operation"
 	BlobovniczaCreatingDirectoryForBoltDB                                   = "creating directory for BoltDB"
 	BlobovniczaOpeningBoltDB                                                = "opening BoltDB"
 	BlobovniczaInitializing                                                 = "initializing..."

pkg/local_object_storage/internal/log/log.go

@@ -1,16 +1,14 @@
 package storagelog
 
 import (
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/logger"
 	"go.uber.org/zap"
 )
 
-// headMsg is a distinctive part of all messages.
-const headMsg = "local object storage operation"
-
 // Write writes message about storage engine's operation to logger.
 func Write(logger *logger.Logger, fields ...zap.Field) {
-	logger.Debug(headMsg, fields...)
+	logger.Debug(logs.StorageOperation, fields...)
 }
 
 // AddressField returns logger's field for object address.