fs/ntfs3: Initialize allocated memory before use

fs/ntfs3: Initialize allocated memory before use

KMSAN reports: Multiple uninitialized values detected:

- KMSAN: uninit-value in ntfs_read_hdr (3)
- KMSAN: uninit-value in bcmp (3)

Memory is allocated by __getname(), which is a wrapper for
kmem_cache_alloc(). This memory is used before being properly
cleared. Change kmem_cache_alloc() to kmem_cache_zalloc() to
properly allocate and clear memory before use.

Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
Fixes: 78ab59fee07f ("fs/ntfs3: Rework file operations")
Tested-by: syzbot+332bd4e9d148f11a87dc@syzkaller.appspotmail.com
Reported-by: syzbot+332bd4e9d148f11a87dc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=332bd4e9d148f11a87dc
Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block")
Fixes: 78ab59fee07f ("fs/ntfs3: Rework file operations")
Tested-by: syzbot+0399100e525dd9696764@syzkaller.appspotmail.com
Reported-by: syzbot+0399100e525dd9696764@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0399100e525dd9696764
Reviewed-by: Khalid Aziz <khalid@kernel.org>
Signed-off-by: Bartlomiej Kubik <kubik.bartlomiej@gmail.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>