disp: msm: dsi: Handle pm_runtime_put_sync return value properly

Currently,power resource disable fails when pm_runtime_put_sync
returns negative values. Due to this, clock state update is
failing. pm_runtime_put_sync can return negative values in
scenarios where  pending resume requests take precedence over
suspends. This change allows pm_runtime_put_sync to return
negative vales also.

Change-Id: I1a46ca574129ba953ddb6300f9b3ab24cdb3171e
Signed-off-by: Lipsa Rout <lrout@codeaurora.org>
Signed-off-by: Steve Cohen <cohens@codeaurora.org>