BACKPORT: powercap: dtpm_cpu: Fix error check against freq_qos_add_request()

The caller of the function freq_qos_add_request() checks again a non
zero value but freq_qos_add_request() can return '1' if the request
already exists. Therefore, the setup function fails while the QoS
request actually did not failed.

Fix that by changing the check against a negative value like all the
other callers of the function.

Bug: 254441685
Fixes: 0e8f68d7 ("Add CPU energy model based support")
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit b50155cb)
[Lee: Fixed trivial surrounding diff conflict - no functional changes intended]
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I7ae72beddcd6c56e51baf6570016b30a33af452d