hdf5_chunking_query_bmr

[svn-r13807] Description:
	Fix error which attempted to allocate space for attribute that has a
'null' dataspace.

Tested on:
	Mac OS X/32 10.4.9 (amazon)
	FreeBSD/32 6.2 (duty)
	Linux/32 2.6 (chicago)
	Linux/64 2.6 (chicago2)