s390/syscalls: Avoid creation of arch/arch/ directory

Building the kernel with ARCH=s390 creates a weird arch/arch/ directory.

  $ find arch/arch
  arch/arch
  arch/arch/s390
  arch/arch/s390/include
  arch/arch/s390/include/generated
  arch/arch/s390/include/generated/asm
  arch/arch/s390/include/generated/uapi
  arch/arch/s390/include/generated/uapi/asm

The root cause is 'targets' in arch/s390/kernel/syscalls/Makefile,
where the relative path is incorrect.

Strictly speaking, 'targets' was not necessary in the first place
because this Makefile uses 'filechk' instead of 'if_changed'.

However, this commit keeps it, as it will be useful when converting
'filechk' to 'if_changed' later.

Fixes: 5c75824 ("s390/syscalls: add Makefile to generate system call header files")
Signed-off-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>

Author: masahir0y

arch/s390/kernel/syscalls/Makefile

@@ -12,7 +12,7 @@ kapi-hdrs-y := $(kapi)/unistd_nr.h
 uapi-hdrs-y := $(uapi)/unistd_32.h
 uapi-hdrs-y += $(uapi)/unistd_64.h
 
-targets += $(addprefix ../../../,$(gen-y) $(kapi-hdrs-y) $(uapi-hdrs-y))
+targets += $(addprefix ../../../../,$(gen-y) $(kapi-hdrs-y) $(uapi-hdrs-y))
 
 PHONY += kapi uapi