cifs: remove dead size-update blocks in cifs_setattr_unix/nounix

Commit 110fee6b9bb5 ("smb: client: fix missing timestamp updates with
O_TRUNC") introduced cifs_file_set_size(), which calls netfs_resize_file()
and cifs_setsize() on success.  cifs_setsize() calls i_size_write(),
updating i_size to the new value.  The subsequent blocks in both
cifs_setattr_unix() and cifs_setattr_nounix():

    if ((attrs->ia_valid & ATTR_SIZE) &&
        attrs->ia_size != i_size_read(inode)) {
        truncate_setsize(inode, attrs->ia_size);
        netfs_resize_file(&cifsInode->netfs, attrs->ia_size, true);
        fscache_resize_cookie(cifs_inode_cookie(inode), attrs->ia_size);
    }

are therefore unreachable on the success path: attrs->ia_size ==
i_size_read(inode) always holds after cifs_file_set_size() succeeds.
On the failure path, execution jumps to out/cifs_setattr_exit before
reaching these blocks.

truncate_setsize() and netfs_resize_file() are redundant with what
cifs_file_set_size() already did; fscache_resize_cookie() was moved there
by commit fa724e235cfd ("cifs: add fscache_resize_cookie() to
cifs_setsize()").  Remove both dead blocks.

Fixes: 110fee6b9bb5 ("smb: client: fix missing timestamp updates with O_TRUNC")
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Reviewed-by: Huiwen He <hehuiwen@kylinos.cn>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>