drm/msm: don't clean up priv->kms prematurely

MSM display drivers provide kms structure allocated during probe().
Don't clean up priv->kms field in case of an error. Otherwise probe
functions might fail after KMS probe deferral.

Fixes: a2ab5d5bb6b1 ("drm/msm: allow passing struct msm_kms to msm_drv_probe()")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Fixes: 506efcba3129 ("drm/msm: carve out KMS code from msm_drv.c")
Patchwork: https://patchwork.freedesktop.org/patch/590411/
Link: https://lore.kernel.org/r/20240420-mdp4-fixes-v1-1-96a70f64fa85@linaro.org