cifs: Fix FALLOC_FL_ZERO_RANGE by setting i_size if EOF moved

Fix the cifs filesystem implementations of FALLOC_FL_ZERO_RANGE, in
smb3_zero_range(), to set i_size after extending the file on the server.

Fixes: 72c419d9

 ("cifs: fix smb3_zero_range so it can expand the file-size when required")
Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Paulo Alcantara <pc@manguebit.com>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: linux-mm@kvack.org
Signed-off-by: Steve French <stfrench@microsoft.com>