Please apply 8f15c682ac5a (rcutorture: Automatically create initrd directory) to 4.19

Hello,

Could you please apply 8f15c682ac5a ("rcutorture: Automatically create initrd directory") to 4.19 stable kernels. The patch made it in 5.0.

This is required to make rcutorture work, without it I get build failures like so:

CC arch/x86/mm/init_64.o CC arch/x86/kernel/cpu/mcheck/mce.o /home/joelaf/repo/chromiumos/chromiumos/src/third_party/kernel/v4.19/arch/x86/entry/entry_64.S: Assembler messages: /home/joelaf/repo/chromiumos/chromiumos/src/third_party/kernel/v4.19/arch/x86/entry/entry_64.S:1762: Warning: no instruction mnemonic suffix given and no register operands; using default for `sysret' AS arch/x86/realmode/rm/stack.o CC arch/x86/kernel/cpu/microcode/core.o AR arch/x86/crypto/built-in.a CC mm/filemap.o CC arch/x86/entry/vdso/vma.o arch/x86/entry/entry_64.o: warning: objtool: .entry.text+0x1c2: unsupported intra-function call arch/x86/entry/entry_64.o: warning: objtool: If this is a retpoline, please patch it in with alternatives and annotate it with ANNOTATE_NOSPEC_ALTERNATIVE. CC arch/x86/kernel/cpu/mtrr/mtrr.o AS arch/x86/realmode/rm/reboot.o AS arch/x86/realmode/rm/wakeup_asm.o CC kernel/bpf/core.o CC fs/autofs/init.o CC arch/x86/realmode/rm/wakemain.o CC fs/debugfs/inode.o CC arch/x86/realmode/rm/video-mode.o CC arch/x86/entry/vsyscall/vsyscall_64.o /home/joelaf/repo/chromiumos/chromiumos/src/third_party/kernel/v4.19/usr/gen_initramfs_list.sh: Cannot open '/home/joelaf/repo/chromiumos/chromiumos/src/third_party/kernel/v4.19/tools/testing/selftests/rcutorture/initrd' `]

thanks,

- Joel