net/mlx5: fw_tracer, Handle escaped percent properly

net/mlx5: fw_tracer, Handle escaped percent properly

[ Upstream commit c0289f67f7d6a0dfba0e92cfe661a5c70c8c6e92 ]

The firmware tracer's format string validation and parameter counting
did not properly handle escaped percent signs (%%). This caused
fw_tracer to count more parameters when trace format strings contained
literal percent characters.

To fix it, allow %% to pass string validation and skip %% sequences when
counting parameters since they represent literal percent signs rather
than format specifiers.

Fixes: 70dd6fdb8987 ("net/mlx5: FW tracer, parse traces and kernel tracing support")
Signed-off-by: Shay Drory <shayd@nvidia.com>
Reported-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Closes: https://lore.kernel.org/netdev/hanz6rzrb2bqbplryjrakvkbmv4y5jlmtthnvi3thg5slqvelp@t3s3erottr6s/
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/1765284977-1363052-5-git-send-email-tariqt@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>