fs/ntfs3: Enable FALLOC_FL_INSERT_RANGE

Changed logic in ntfs_fallocate - more clear checks in beginning
instead of the middle of function and added FALLOC_FL_INSERT_RANGE.
Fixes xfstest generic/064
Fixes: 4342306f ("fs/ntfs3: Add file operations and implementation")

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>