math: fft: fix error path in mod_fft_multi_plan_new() #23656

Job	Run time
build-windows (mnfst, imx8 imx8x)	3m 7s
LP64-WIP	3m 3s
build-linux (mnfst, imx8m imx8ulp)	3m 31s
build-windows (mnfst, mtl)	3m 15s
manifest-check	2m 46s
build-linux (mnfst, tgl)	3m 10s
build-windows (mnfst, tgl-h)	3m 12s
build-windows (mnfst, tgl)	3m 23s
build-windows (mnfst, imx8m imx8ulp)	3m 7s
build-linux (mnfst, lnl)	3m 22s
build-linux (-d, mnfst, lnl)	3m 18s
build-linux (mnfst, imx8 imx8x)	3m 9s
build-linux (mnfst, tgl-h)	3m 30s
build-windows (-d, mnfst, lnl)	3m 23s
build-windows (mnfst, lnl)	3m 7s
build-linux (mnfst, mtl)	3m 31s
build-windows (mnfst, ptl)	3m 19s
build-linux (mnfst, ptl)	3m 36s
build-linux (mnfst, wcl imx95)	3m 38s
compare-linux-win	44s
	1h 3m 11s

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