[PATCH] serial: vt8500: Use devm_clk_get_enabled()

[Wentao Liang]

Hi Alexey,

Sorry for the very late reply. Working through the review comments I got
in September has taken me far longer than it should have.

Your suggestion was right, but the leak fix went in before I could act on
it: it is commit 9d8955281d92 ("serial: vt8500: Fix clock reference leak
in vt8500_serial_probe()") in mainline, and it kept the clk_put() you
asked me to replace. It has been backported to the stable trees by now as
well. So the patch below is not a v2 of that one, which would only resend
something that is already applied, but a follow-up that does the
conversion on top of it.

devm_clk_get_enabled() gets the clock and enables it in one call and
registers the disable and put with devm, so both the manual error handling
and the clk_put() go away. Probe now returns the error code from the clock
lookup instead of a hard-coded -EINVAL, and the clock is released
automatically through devres. The success path is unchanged and nothing
else in the driver is touched.

For the record on where this came from: the candidate came from our static
analysis tooling, and DeepSeek and GPT-6.1 Sol were used to audit it and to
help write the change. I reviewed the result and I am responsible for it.
The patch is build-tested only: it compiles cleanly with W=1 for arm
(vt8500_v6_v7_defconfig, CONFIG_SERIAL_VT8500=y) and passes
checkpatch.pl --strict; I have no VT8500 hardware to test it on.

Thanks for the review,
Wentao