Kernel: Make device generate their own names

Besides removing the monolithic DevFSDeviceInode::determine_name()
method, being able to determine a device's name inside the /dev
hierarchy outside of DevFS has its uses.

Kernel/Storage/RamdiskDevice.cpp

@@ -82,4 +82,11 @@ void RamdiskDevice::start_request(AsyncBlockDeviceRequest& request)
     }
 }
 
+String RamdiskDevice::device_name() const
+{
+    // FIXME: Try to not hardcode a maximum of 16 partitions per drive!
+    size_t drive_index = minor() / 16;
+    return String::formatted("ramdisk{}", drive_index);
+}
+
 }