imsm: check migration compatibility

imsm: check migration compatibility

Under Windows IMSM can reshape arrays in 2 directions
(ascending and decsending).
Under Linux one (ascending) direction is supported at this moment.
Block loading metadata when decsending reshape is detected

Windows also uses optimalization area during reshaping array.
Linux does not support it.
The patch blocks this operation also.

Signed-off-by: Maciej Trela <maciej.trela@intel.com>
Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: Krzysztof Wojcik <krzysztof.wojcik@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>