Audio: STFT Process: Fix doxygen syntax error #22139

Job	Run time
LP64-WIP	3m 52s
build-windows (-d, lnl)	9m 45s
manifest-check	2m 50s
build-windows (mtl lnl)	10m 5s
build-windows (imx8 imx8x imx8m imx8ulp)	14m 49s
build-windows (tgl tgl-h)	11m 52s
build-windows (ptl)	10m 53s
build-linux (mnfst, mtl lnl)	5m 20s
build-linux (zmain, imx8 imx8x imx8m imx8ulp)	6m 38s
build-linux (zmain, ptl)	5m 5s
build-linux (zmain, mtl lnl)	5m 45s
build-linux (mnfst, tgl tgl-h)	5m 36s
build-linux (zmain, tgl tgl-h)	5m 20s
build-linux (mnfst, imx8 imx8x imx8m imx8ulp)	6m 46s
build-linux (mnfst, wcl imx95)	7m 5s
build-linux (-d, mnfst, lnl)	4m 27s
build-linux (mnfst, ptl)	5m 51s
compare-linux-win	30s
	2h 2m 29s

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