msm: mdss: avoid removing wrong multirect on validate failures

During atomic commit - validate failures, the newly allocated
pipes and pipes taken from the destroy list are cleaned up.
Currently pipe ndx is checked which can lead to cleaning up
the already in use multirect instead of the rect allocated
in the current validate. Add checks to include checking based
on multirect to avoid such cases.

Change-Id: Icbc7e390110ccfbbe65645711b47d1eff8f60fa2
Signed-off-by: Ramakant Singh <ramaka@codeaurora.org>