fs/ntfs3: Delete duplicate condition in ntfs_read_mft()

There were two patches which addressed the same bug and added the same
condition:

commit 6db62086 ("fs/ntfs3: Validate data run offset")
commit 887bfc54 ("fs/ntfs3: Fix slab-out-of-bounds read in run_unpack")

Delete one condition.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>