From: Merav Sicron <meravs@broadcom.com>

Current ethtool self tests usesa large buffer on stack. This patch replaces
that array by dynamically allocated memory
Signed-off-by: NMerav Sicron <meravs@broadcom.com>
Signed-off-by: NEilon Greenstein <eilong@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>