ethtool: Remove unnecessary null check in ethtool_rx_flow_rule_create

net/core/ethtool.c:3023:19: warning: address of array
'ext_m_spec->h_dest' will always evaluate to 'true'
[-Wpointer-bool-conversion]
                if (ext_m_spec->h_dest) {
                ~~  ~~~~~~~~~~~~^~~~~~

h_dest is an array, it can't be null so remove this check.

Fixes: eca4205f

 ("ethtool: add ethtool_rx_flow_spec to flow_rule structure translator")
Link: https://github.com/ClangBuiltLinux/linux/issues/353
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>