Even better test the modules deletion pipeline

Now works when there's only one directory in modules (matching the
kernel) and when kernels are substrings of each other

config/scripts/regen-initramfs.sh

@@ -2,9 +2,10 @@
 set -oue pipefail
 
 KVER="$(rpm -q kernel | sed -rn 's/^kernel-(.*)$/\1/p')"
-ls -1 /usr/lib/modules | grep -vZ "$KVER" | sed -z 's/[[:space:]]*$//' \
-    | xargs -0 -- printf "/usr/lib/modules/%s\0" \
-    | xargs -0 -- rm -rf
+ls -1 --zero /usr/lib/modules | grep -vz "^$KVER$" \
+    | sed -z 's/[[:space:]]*$//' \
+    | xargs -r -0 -- printf "/usr/lib/modules/%s\0" \
+    | xargs -r -0 -- rm -rf
 
 mkdir -p /tmp/dracut
 dracut --reproducible -v --add 'ostree' --tmpdir '/tmp/dracut' -f --no-hostonly --kver $KVER "/usr/lib/modules/$KVER/initramfs.img"