[NOT FOR UPSTREAM] ASoC: SOF: ipc4-mtrace: Fix NULL dereference on reboot caused by not for upstream patch #7768

Job	Run time
GCC static -fanalyzer	3m 52s
Sparse check	2m 59s
GCC build X86_64 with W=1 allmodconfig	1m 46s
GCC build X86_64 with W=1	2m 56s
GCC build i386	16m 2s
GCC build X86_64	20m 1s
GCC build arm64 allmodconfig	1m 52s
Clang build x86_64	4m 32s
GCC build arm64	19m 39s
	1h 13m 39s

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