drm/msm/sde: check frame pending status before failure trigger

HW might miss to trigger the CTL_START IRQ but frame trigger
was still successful. This can be confirmed by checking the
controller state. Avoid failure trigger if frame transfer
was successful.

Change-Id: I21596029f24dc9ccf80eacb40bc4925d807c61ef
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>