Assume media is non-rotational by default

src/disk_util.hpp

@@ -42,15 +42,15 @@ namespace DiskUtil {
     inline bool IsRotational(const std::string &dir)
     {
 #if defined(__APPLE__) || defined(_WIN32)
-        return true;
+        return false;
 #else
         struct stat s{};
 
         if (0 != stat(dir.c_str(), &s)) {
             std::ostringstream err;
             std::cerr << "Unable to find device name for dir " << dir << ": "
                 << strerror(errno);
-            return true;
+            return false;
         }
 
         int major_id = major(s.st_dev);
@@ -68,20 +68,15 @@ namespace DiskUtil {
             std::ostringstream err;
             std::cerr << "Unable to open " << filename << " for reading: "
                 << strerror(errno);
-            return true;
+            return false;
         }
 
         std::string line;
         getline(file, line);
 
         file.close();
 
-        int is_rotational = 1;
-        if (!line.empty() && line.front() == '0') {
-            is_rotational = 0;
-        }
-
-        return is_rotational;
+        return !line.empty() && line.front() == '1';
 #endif
     }