fs/ntfs3: fix KMSAN uninit-value in ni_create_attr_list
The call to kmalloc() to allocate the attribute list buffer is given a
size of al_aligned(rs). This size can be larger than the data
subsequently copied into the buffer, leaving trailing bytes uninitialized.
This can trigger a KMSAN "uninit-value" warning if that memory is
later accessed.
Fix this by using kzalloc() instead, which ensures the entire
allocated buffer is zero-initialized, preventing the warning.