When searching a matching extension for a file, also check for the empty extension.

scripts/functions

@@ -244,7 +244,10 @@ CT_GetFileExtension() {
     local got_it=1
 
     CT_Pushd "${CT_TARBALLS_DIR}"
-    for ext in .tar.gz .tar.bz2 .tgz .tar; do
+    # we need to also check for an empty extension for those very
+    # peculiar components that don't have one (such as sstrip from
+    # buildroot).
+    for ext in .tar.gz .tar.bz2 .tgz .tar ''; do
         if [ -f "${file}${ext}" ]; then
             echo "${ext}"
             got_it=0