msm: mdss: replace init_completion with reinit_completion

Use reinit_completion to reinit complete signal, init_completion
function and complete/complete_all function that happens
simultaneously causes deadlock.

Change-Id: I5cda23999b6f9f86e790bb9356c65e1424a17cf9
Signed-off-by: Arun kumar <akanak@codeaurora.org>