fix linter error, mv const to config

cmd/alloc.go

@@ -7,17 +7,10 @@ import (
 	"github.com/ncw/directio"
 )
 
-const (
-	O_R = iota
-	O_W
-	O_RW
-)
-
 // aligned allocs used for testing
 type Alloc struct {
 	writeBlock []byte
 	readBlock  []byte
-	mode       int
 }
 
 // zero the memory blocks

cmd/config.go

@@ -28,6 +28,10 @@ Options:
 -d --debug                    Enable debug log level
 -h --help                     Show help
 -v --version                  Show program version`
+
+	O_R = iota
+	O_W
+	O_RW
 )
 
 // config via commandline flags