nfp: flower: Fix a potential leak in nfp_tunnel_add_shared_mac()

stable inclusion
from stable-v5.10.103
commit af4bc921d39dffdb83076e0a7eed1321242b7d87
bugzilla: https://gitee.com/openeuler/kernel/issues/I56NE7

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=af4bc921d39dffdb83076e0a7eed1321242b7d87



--------------------------------

commit 3a14d088 upstream.

ida_simple_get() returns an id between min (0) and max (NFP_MAX_MAC_INDEX)
inclusive.
So NFP_MAX_MAC_INDEX (0xff) is a valid id.

In order for the error handling path to work correctly, the 'invalid'
value for 'ida_idx' should not be in the 0..NFP_MAX_MAC_INDEX range,
inclusive.

So set it to -1.

Fixes: 20cce886 ("nfp: flower: enable MAC address sharing for offloadable devs")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/20220218131535.100258-1-simon.horman@corigine.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>