i2c: tegra: make tegra_i2c_mutex_unlock() return void

i2c: tegra: make tegra_i2c_mutex_unlock() return void

tegra_i2c_mutex_unlock() returning an error that overwrites the transfer
result causes silent loss of I2C transfer errors. If the transfer failed
but the unlock succeeded, the error was lost and the function incorrectly
reported success.

Rather than propagating the unlock error (which is not actionable by the
caller - the I2C message may have been sent regardless), convert the
function to return void and WARN on the unexpected condition. If the
unlock fails, subsequent lock attempts will fail anyway, making the error
visible on the next transfer.

Fixes: 6077cfd716fb ("i2c: tegra: Add support for SW mutex register")
Signed-off-by: Saurav Sachidanand <sauravsc@amazon.com>
Cc: <stable@vger.kernel.org> # v7.0+
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20260507221145.62183-3-sauravsc@amazon.com