Revert "msm: kgsl: Offload mementry destroy work to separate thread"

This reverts commit 281fcb5e184b9d1074dd404016cebacce12a8664.

To address the issue with the OOMkiller causing to kill the
foreground application.

Change-Id: Ie4c078d706fdf1c13ad45840f72b414ddc37c1d0
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
Signed-off-by: Venkateswara Rao Tadikonda <vtadik@codeaurora.org>