mdss: compat: suppress unnecessary prints

Some overlay ioctls would fail in order to indicate that a user
request cannot be satisfied due to, say, resource constraints.
Such failures could depend on a particular target's
capabilities. In such cases, it is not fatal to return error.
Suppress printing such failures as errors.

Change-Id: I163d6c21055527a8d5f0adf09af0debc54e47751
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>