Show partitions that have a file system in list of bootable partitions only.

This fixes part 2 of ticket #2477.
Next is to implement the ioctl B_GET_BIOS_DRIVE_ID, any taker?

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27149 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/bootman/LegacyBootDrive.cpp

@@ -169,6 +169,9 @@ PartitionRecorder::FirstOffset() const
 bool
 PartitionRecorder::_Record(BPartition* partition)
 {
+	if (!partition->ContainsFileSystem())
+		return false;
+	
 	BPath partitionPath;
 	partition->GetPath(&partitionPath);