Revert "kexec/purgatory: Add clean-up for purgatory directory"

Revert "kexec/purgatory: Add clean-up for purgatory directory"

Reverts the following commit:

  b0108f9e93d0 ("kexec: purgatory: add clean-up for purgatory directory")

... which incorrectly stated that the kexec-purgatory.c and purgatory.ro files
were not removed after 'make mrproper'.

In fact, they are.  You can confirm it after reverting it.

  $ make mrproper
  $ touch arch/x86/purgatory/kexec-purgatory.c
  $ touch arch/x86/purgatory/purgatory.ro
  $ make mrproper
    CLEAN   arch/x86/purgatory
  $ ls arch/x86/purgatory/
  entry64.S  Makefile  purgatory.c  setup-x86_64.S  stack.S  string.c

This is obvious from the build system point of view.

arch/x86/Makefile adds 'arch/x86' to core-y.
Hence 'make clean' descends like this:

  arch/x86/Kbuild
    -> arch/x86/purgatory/Makefile

Signed-off-by: Masahiro Yamada <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michal Marek <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>