kernel/zarch: Fix cscal and zscal #5707

Job	Run time
msys2 (UCRT64, int64, Release)	1h 37m 57s
msys2 (UCRT64, int32, Release)	1h 38m 45s
msys2 (CLANG64, int64, Release)	1h 11m 15s
msys2 (MINGW32, int32, Release)	1h 4m 36s
msys2 (CLANG64, int32, Release)	1h 16m 21s
build (ubuntu-latest, gfortran, make)	22m 11s
msys2 (UCRT64, int32, None, mingw-w64-ucrt-x86_64, fc)	1h 27m 43s
build (ubuntu-latest, flang, make)	18m 36s
build (macos-latest, gfortran, make)	10m 52s
build (ubuntu-latest, flang, cmake)	45m 1s
neoverse_build	9m 5s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	9m 30s
build (ubuntu-latest, gfortran, cmake)	44m 58s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	8m 6s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	7m 26s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	9m 36s
build (macos-latest, gfortran, cmake)	29m 16s
	11h 51m 14s

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