use rpm lua to sanitize the upstream version string

Like in Fedora perftest-4.5.0.20-4.fc38.

Resolves: rhbz#2167405
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

perftest.spec

@@ -1,11 +1,11 @@
 Name:           perftest
 Summary:        IB Performance Tests
 # Upstream uses a dash in the version. Not valid in the Version field, so we use a dot instead.
+# Issue "Please avoid dashes in version":
+#   https://github.com/linux-rdma/perftest/issues/18
 %global upstream_ver 4.5-0.20
-# The directory in the tarball has only the part before the dash.
-%global tarball_ver 4.5
-Version:        4.5.0.20
-Release:        1%{?dist}
+Version:        %{lua: print((string.gsub(rpm.expand("%{upstream_ver}"),"-",".")))}
+Release:        4%{?dist}
 License:        GPLv2 or BSD
 Source:         https://github.com/linux-rdma/perftest/releases/download/v4.5-0.20/perftest-4.5-0.20.gac7cca5.tar.gz
 Url:            https://github.com/linux-rdma/perftest
@@ -26,6 +26,9 @@ connections.  It does not work on normal TCP/IP networks, only on
 RDMA networks.
 
 %prep
+# The directory in the tarball has only the part before the dash.
+%global tarball_ver %{lua: _,_,v=string.find(rpm.expand("%{upstream_ver}"),"([^-]+)"); print(v)}
+
 %setup -q -n %{name}-%{tarball_ver}
 find src -type f -iname '*.[ch]' -exec chmod a-x '{}' ';'
 
@@ -44,6 +47,10 @@ done
 %_bindir/*
 
 %changelog
+* Tue Feb 07 2023 Michal Schmidt <mschmidt@redhat.com> - 4.5.0.20-4
+- Use rpm lua code from Fedora perftest-4.5.0.20-4.fc38.
+- Resolves: rhbz#2167405
+
 * Mon Feb 06 2023 Kamal Heib <kheib@redhat.com> - 4.5.0.20-1
 - Rebase to upstream release perftest-4.5-0.20
 - Resolves: rhbz#2167405