LLEXT: fix a memory leak #20239

Job	Run time
LP64-WIP	4m 44s
build-windows (imx8 imx8x imx8m imx8ulp)	8m 49s
build-windows (mtl lnl)	7m 27s
manifest-check	53s
build-windows (ptl)	6m 9s
build-windows (tgl tgl-h)	6m 52s
build-linux (mnfst, ptl)	5m 11s
build-linux (zmain, mtl lnl)	5m 52s
build-linux (zmain, imx8 imx8x imx8m imx8ulp)	6m 16s
build-linux (zmain, ptl)	4m 42s
build-windows (-d, lnl)	5m 52s
build-linux (mnfst, imx8 imx8x imx8m imx8ulp)	6m 22s
build-linux (mnfst, --all)	14m 13s
build-linux (-d, mnfst, lnl)	4m 27s
build-linux (mnfst, mtl lnl)	5m 48s
build-linux (zmain, tgl tgl-h)	5m 34s
build-linux (mnfst, tgl tgl-h)	6m 6s
compare-linux-win	39s
	1h 45m 56s

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