msm: mdss: fix error handling in pan display commit path

Pan display commit leaves the left ctl pipe allocated if
right ctl pipe allocation fails. It also tries to release
the iommu refcount when it did not added it. This can lead
to pipe allocation failure for atomic commit or page fault
due to smmu clock disable. This change fixes the error
handling in pan display commit path to release the resources
in correct order.

Change-Id: Icaa0cf164d12fe3f8d4d2012917a5524ad31f824
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>