fix VM_CAN_NONLINEAR check in sys_remap_file_pages

The test for VM_CAN_NONLINEAR always fails

Signed-off-by: Yan <Zheng&lt;yanzheng@21cn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>