MINOR: pattern: make the pattern matching function return a pointer to the matched element

This feature will be used by the CLI to look up keys.
diff --git a/include/proto/pattern.h b/include/proto/pattern.h
index ee19392..8c9c1c7 100644
--- a/include/proto/pattern.h
+++ b/include/proto/pattern.h
@@ -58,7 +58,7 @@
  * associated to the matching patterned will be put there. The function returns
  * PAT_MATCH or PAT_NOMATCH.
  */
-enum pat_match_res pattern_exec_match(struct pattern_expr *expr, struct sample *smp, struct sample_storage **sample);
+enum pat_match_res pattern_exec_match(struct pattern_expr *expr, struct sample *smp, struct sample_storage **sample, struct pattern **pat, struct pat_idx_elt **elt);
 
 /*
  *