dax: Add block size note to documentation
dax: Add block size note to documentation

For block devices which are small enough, mkfs will default to creating
a filesystem with block sizes smaller than page size.

Signed-off-by: Matthew Wilcox <990c37a323daf1549bdd24197927625080ee16b8@linux.intel.com>
Signed-off-by: Al Viro <de609eb4d5d70b1d38ec6642adbfc33a2781f63c@zeniv.linux.org.uk>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs