x86/vdso: Consolidate targets and clean-files

'targets' and 'clean-files' do not need to list the same files because
the files listed in 'targets' are cleaned up.

Refactor the code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231121235701.239606-2-masahiroy@kernel.org

Author: masahir0y

arch/x86/entry/vdso/Makefile

@@ -55,11 +55,8 @@ targets += vdso32/vdso32.lds $(vobjs32-y)
 
 # Build the vDSO image C files and link them in.
 vdso_img_objs := $(vdso_img-y:%=vdso-image-%.o)
-vdso_img_cfiles := $(vdso_img-y:%=vdso-image-%.c)
-vdso_img_sodbg := $(vdso_img-y:%=vdso%.so.dbg)
 obj-y += $(vdso_img_objs)
-targets += $(vdso_img_cfiles)
-targets += $(vdso_img_sodbg) $(vdso_img-y:%=vdso%.so)
+targets += $(foreach x, 64 x32 32, vdso-image-$(x).c vdso$(x).so vdso$(x).so.dbg)
 
 CPPFLAGS_vdso.lds += -P -C
 
@@ -190,5 +187,3 @@ GCOV_PROFILE := n
 
 quiet_cmd_vdso_and_check = VDSO    $@
       cmd_vdso_and_check = $(cmd_vdso); $(cmd_vdso_check)
-
-clean-files := vdso32.so vdso32.so.dbg vdso64* vdso-image-*.c vdsox32.so*