Fix minor filesystem bugs (#2563)

- Fix return value from Spiffs `fenumxattr()`: Should return number of attributes read.
- Fix LittleFS `FileSystem::format()` return value: int not bool
- Remove (non-const) `Device::partitions()` method: Partition table is always accessed read-only
- Remove `Partition::getDevice()` method: Could be used to bypass protections offered by partitioning API
- Fix `IFS::Stat::printTo()` timestamp printing: Shows numeric (time_t) value instead of string

Sming/Components/Storage/src/include/Storage/Device.h

@@ -56,11 +56,6 @@ class Device : public LinkedObjectTemplate<Device>
 		return getName() == name;
 	}
 
-	PartitionTable& partitions()
-	{
-		return mPartitions;
-	}
-
 	const PartitionTable& partitions() const
 	{
 		return mPartitions;

Sming/Components/Storage/src/include/Storage/Partition.h

@@ -334,15 +334,6 @@ class Partition
 	 */
 	String getDeviceName() const;
 
-	/**
-	 * @brief Get storage device containing this partition
-	 * @retval Device* null if device isn't registered
-	 */
-	Device* getDevice() const
-	{
-		return mDevice;
-	}
-
 	/**
 	 * @brief Determine if given address contained within this partition
 	 */

Sming/Components/Storage/src/include/Storage/PartitionTable.h

@@ -77,7 +77,7 @@ class PartitionTable
 	/**
 	 * @brief Find the n'th OTA partition
 	 */
-	Partition findOta(uint8_t index)
+	Partition findOta(uint8_t index) const
 	{
 		using App = Partition::SubType::App;
 		auto subtype = App(uint8_t(App::ota0) + index);

Sming/Libraries/Spiffs/src/FileMeta.cpp

@@ -59,6 +59,7 @@ int SpiffsMetaBuffer::enumxattr(AttributeEnumCallback callback, void* buffer, si
 			continue;
 		}
 		e.set(tag, value, getAttributeSize(tag));
+		++count;
 		if(!callback(e)) {
 			return count;
 		}
@@ -72,6 +73,7 @@ int SpiffsMetaBuffer::enumxattr(AttributeEnumCallback callback, void* buffer, si
 			break;
 		}
 		e.set(AttributeTag(unsigned(AttributeTag::User) + tagIndex), &user[i], tagSize);
+		++count;
 		if(!callback(e)) {
 			break;
 		}