FIX: mdmon check in reshape_container() can cause a problem

FIX: mdmon check in reshape_container() can cause a problem

When raid0 reshape is executed mdmon can dissappear due to raid level
takeover operation. If this happen before mdmon check, mdadm would treat
it as error condition. It is not true for this case.

Remove mdmon check from reshape_container() function.
Error condition check will remain using reshape_array() reentry test
for the same array (line 2577).

Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>