[PATCH] net/mlx5e: Return in default case statement in tx_post_resync_params

[Nathan Chancellor <natechancellor@xxxxxxxxx>]

clang warns:

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c:251:2:
warning: variable 'rec_seq_sz' is used uninitialized whenever switch
default is taken [-Wsometimes-uninitialized]
        default:
        ^~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c:255:46: note:
uninitialized use occurs here
        skip_static_post = !memcmp(rec_seq, &rn_be, rec_seq_sz);
                                                    ^~~~~~~~~~
drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c:239:16: note:
initialize the variable 'rec_seq_sz' to silence this warning
        u16 rec_seq_sz;
                      ^
                       = 0
1 warning generated.

This case statement was clearly designed to be one that should not be
hit during runtime because of the WARN_ON statement so just return early
to prevent copying uninitialized memory up into rn_be.

Fixes: d2ead1f360e8 ("net/mlx5e: Add kTLS TX HW offload support")
Link: https://github.com/ClangBuiltLinux/linux/issues/590
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
index 3f5f4317a22b..5c08891806f0 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_accel/ktls_tx.c
@@ -250,6 +250,7 @@ tx_post_resync_params(struct mlx5e_txqsq *sq,
 	}
 	default:
 		WARN_ON(1);
+		return;
 	}
 
 	skip_static_post = !memcmp(rec_seq, &rn_be, rec_seq_sz);
-- 
2.22.0