sde: Remove redundant PostPrepare in Prepare function

PostPrepare function is being called twice on successful Prepare.
Remove redundant PostPrepare calls in Prepare() function.

Change-Id: I84f23337c49828d58f9a064146be1b041c39c156
diff --git a/displayengine/libs/core/display_base.cpp b/displayengine/libs/core/display_base.cpp
index dac17fd..d403450 100644
--- a/displayengine/libs/core/display_base.cpp
+++ b/displayengine/libs/core/display_base.cpp
@@ -152,12 +152,9 @@
       if (error == kErrorNone) {
         error = hw_intf_->Validate(hw_device_, &hw_layers_);
         if (error == kErrorNone) {
-          error = comp_manager_->PostPrepare(display_comp_ctx_, &hw_layers_);
-          if (error == kErrorNone) {
-            // Strategy is successful now, wait for Commit().
-            pending_commit_ = true;
-            break;
-          }
+          // Strategy is successful now, wait for Commit().
+          pending_commit_ = true;
+          break;
         }
       }
     }