tools/tests: Fix return value of test-rangeset

Otherwise, failed tests are ignored by automated test.

Fixes: 7bf777b42c ("tootls/tests: introduce unit tests for rangesets")
Signed-off-by: Anthony PERARD <anthony.perard@vates.tech>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

tools/tests/rangeset/test-rangeset.c

@@ -215,7 +215,7 @@ int main(int argc, char **argv)
         }
     }
 
-    return 0;
+    return ret_code;
 }
 
 /*