kbuild: use proper prefix for tarballs to fix rpm-pkg build error

Since commit f8d94c4 ("kbuild: do not create intermediate *.tar
for source tarballs"), 'make rpm-pkg' fails because the prefix of the
source tarball is 'linux.tar/' instead of 'linux/'. $(basename $@)
strips only '.gz' from the filename linux.tar.gz.

You need to strip two suffixes from compressed tarballs and one suffix
from uncompressed tarballs (for example 'perf-6.3.0.tar' generated by
'make perf-tar-src-pkg').

One tricky fix might be --prefix=$(firstword $(subst .tar, ,$@))/
but I think it is better to hard-code the prefix.

Fixes: f8d94c4 ("kbuild: do not create intermediate *.tar for source tarballs")
Reported-by: Jiwei Sun <sunjw10@lenovo.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>

scripts/Makefile.package

@@ -49,15 +49,15 @@ git-config-tar.zst = -c tar.tar.zst.command="$(ZSTD)"
 
 quiet_cmd_archive = ARCHIVE $@
       cmd_archive = git -C $(srctree) $(git-config-tar$(suffix $@)) archive \
-                    --output=$$(realpath $@) --prefix=$(basename $@)/ $(archive-args)
+                    --output=$$(realpath $@) $(archive-args)
 
 # Linux source tarball
 # ---------------------------------------------------------------------------
 
 linux-tarballs := $(addprefix linux, .tar.gz)
 
 targets += $(linux-tarballs)
-$(linux-tarballs): archive-args = $$(cat $<)
+$(linux-tarballs): archive-args = --prefix=linux/ $$(cat $<)
 $(linux-tarballs): .tmp_HEAD FORCE
 	$(call if_changed,archive)
 
@@ -189,7 +189,7 @@ perf-archive-args = --add-file=$$(realpath $(word 2, $^)) \
 perf-tarballs := $(addprefix perf-$(KERNELVERSION), .tar .tar.gz .tar.bz2 .tar.xz .tar.zst)
 
 targets += $(perf-tarballs)
-$(perf-tarballs): archive-args = $(perf-archive-args)
+$(perf-tarballs): archive-args = --prefix=perf-$(KERNELVERSION)/ $(perf-archive-args)
 $(perf-tarballs): tools/perf/MANIFEST .tmp_perf/HEAD .tmp_perf/PERF-VERSION-FILE FORCE
 	$(call if_changed,archive)