lib/file/stat: don't set bsize for non-blob entities
lib/file/stat: don't set bsize for non-blob entities

It doesn't make much sense, as these entities don't accept IO. Also,
this simplifies the block blob stat implementation, which will share
root, account and container functions.

Signed-off-by: David Disseldorp <589a549dc9f982d9f46aeeb82a09ab6d87ccf1d8@suse.de>

ddiss/elasto,ddiss/elasto