[svn-r12022] Purpose: Small bug fix

Description: Return value from H5Pget_layout is 0 for the compact datasets;
             It was assumed in the code that it was always greater than 0; therefore
             assertion failed when h5stat walked a compact dataset.

Solution: Fixed assertion statement

Platforms tested: h5stat doesn't have testscript yet; tested manually
                  with tfilters.h5 file on heping.
                  Fix is too minor to test it on multiple platforms.

Misc. update:

tools/misc/h5stat.c

@@ -447,7 +447,7 @@ printf("walk: fullname = %s\n", fullname);
                 assert(dcpl > 0);
 
                 lout = H5Pget_layout(dcpl);
-                assert(lout > 0);
+                assert(lout >= 0);
 
                 /* Track the layout type for dataset */
                 (iter->dset_layouts[lout])++;