mke2fs: don't set stripe/stride to 1 block

mke2fs: don't set stripe/stride to 1 block

Block devices may set minimum or optimal IO hints equal to
blocksize; in this case there is really nothing for ext4
to do with this information (i.e. search for a block-aligned
allocation?) so don't set fs geometry with single-block
values.

Zeev also reported that with a block-sized stripe, the
ext4 allocator spends time spinning in ext4_mb_scan_aligned(),
oddly enough.

Reported-by: Zeev Tarantov <zeev.tarantov@gmail.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>