Description: drm/amdkfd: Check for null pointer after calling kmemdup
References:
 https://bugzilla.redhat.com/show_bug.cgi?id=2153052
Notes:
 bwh> Introduced in 4.16 by commit 3a87177eb141 "drm/amdkfd: Add topology
 bwh> support for dGPUs".
Bugs:
upstream: released (5.17-rc1) [abfaf0eee97925905e742aa3b0b72e04a918fa9e]
6.1-upstream-stable: N/A "Fixed before branch point"
5.10-upstream-stable: needed
4.19-upstream-stable: needed
sid: released (5.16.7-1)
6.1-bookworm-security: N/A "Fixed before branch point"
5.10-bullseye-security: needed
4.19-buster-security: needed