Variables starting with `d' in bsd/hfs

• d bsd/hfs/hfs.h:426
• Delete bsd/hfs/hfs_vfsutils.c:666
• doclusterread bsd/hfs/hfs_readwrite.c:138
• doclusterwrite bsd/hfs/hfs_readwrite.c:139
• drAllocPtr bsd/hfs/hfs_vfsutils.c:218
• drVolBkUp bsd/hfs/hfs_vfsutils.c:214