ppmgr: Add IS_ERR_OR_NULL to determine if the thread exists [1/1]

PD#SWPL-8658

Problem:
handle is NULL cause kernel panic.

Solution:
Add IS_ERR_OR_NULL to prevent hanle from being NULL
to cause kernel panic.

Verify:
on T962X2

Change-Id: I3086a497d99646e6475a93b5a53b3c9aca2d2ada
Signed-off-by: renjiang.han <renjiang.han@amlogic.com>
1 file changed