debian/scripts: use printf to ensure \t is actually printewd as tab

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

debian/scripts/export-patchqueue

@@ -6,7 +6,7 @@ top=$(pwd)
 
 if [ "$#" -ne 3 ]; then
     echo "USAGE: $0 repo patchdir ref"
-    echo "\t exports patches from 'repo' to 'patchdir' based on 'ref'"
+    printf "\t exports patches from 'repo' to 'patchdir' based on 'ref'\n"
     exit 1
 fi
 
@@ -30,6 +30,6 @@ git format-patch \
     "${top}/${kernel_patchdir}" \
     "${base_ref}.."
 
-git checkout ${base_ref}
+git checkout "${base_ref}"
 
 cd "${top}"