cpufreq/amd-pstate: Fix cpufreq_policy ref counting

cpufreq/amd-pstate: Fix cpufreq_policy ref counting

amd_pstate_update_limits() takes a cpufreq_policy reference but doesn't
decrement the refcount in one of the exit paths, fix that.

Fixes: 45722e777fd9 ("cpufreq: amd-pstate: Optimize amd_pstate_update_limits()")
Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/r/20250205112523.201101-10-dhananjay.ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>