pch_gbe: fix bogus trylock conversion

Should have converted 'if (trylock)' to 'lock'.

Fixes: a6086a89 ("drivers: net: remove NETDEV_TX_LOCKED")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>