drm/msm: remove unlikely() from WARN_ON() conditions

"unlikely(WARN_ON(x))" is excessive. WARN_ON() already uses unlikely()
internally.

Signed-off-by: Denis Efremov <efremov@linux.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>