net: ena: add newline at the end of pr_err prints

Some pr_err prints lacked '\n' in the end. Added where missing.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>