layers: Fix pNext chaining for DRM #10867

Job	Run time
code-format	29s
check_vvl	1m 20s
Ubuntu Backcompat	2m 51s
linux (address sanitizer, release, robinhood ON )	20m 54s
linux (address sanitizer, release, robinhood OFF )	21m 7s
android (arm64-v8a, ON, c++_shared)	9m 38s
androidOnLinux	4m 7s
chromium (target_os="linux" target_cpu="x64")	8m 3s
android (armeabi-v7a, OFF, c++_static)	5m 46s
linux (Build Only, debug, robinhood ON )	11m 45s
chromium (target_os="android" target_cpu="arm64")	10m 52s
linux (thread sanitizer, release, robinhood ON )	5m 56s
mingw	3m 29s
windows (amd64)	16m 10s
windows (amd64_x86)	15m 46s
iOS	5m 4s
androidUpload	0s
windowsUpload	0s
linux Upload	0s
	2h 23m 17s

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