lint: fix warnings found by protogetter

features.GetMemTrack() already does all the pointer checks so we can
just use it.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

pkg/criu/criu_linux.go

@@ -37,11 +37,7 @@ func MemTrack() bool {
 		return false
 	}
 
-	if features == nil || features.MemTrack == nil {
-		return false
-	}
-
-	return *features.MemTrack
+	return features.GetMemTrack()
 }
 
 func GetCriuVersion() (int, error) {