net: hns: Add missing \n to end of dev_err messages, tidy up text

Trival fix, dev_err messages are missing a \n, so add it. Also
fix grammer, spelling mistake and add white spaces to various
error messages.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>