MINOR: acl: Extract the pattern matching function

The map feature will need to match acl patterns. This patch extracts
the matching function from the global ACL function "acl_exec_cond".

The code was only moved to its own function, no functional changes were made.
diff --git a/include/proto/acl.h b/include/proto/acl.h
index f50c289..008e848 100644
--- a/include/proto/acl.h
+++ b/include/proto/acl.h
@@ -138,6 +138,11 @@
  */
 struct acl *find_acl_by_name(const char *name, struct list *head);
 
+/* This function execute the match part of the acl.
+ * it return ACL_PAT_FAIL, ACL_PAT_MISS or ACL_PAT_PASS
+ */
+inline int acl_exec_match(struct acl_expr *expr, struct sample *smp);
+
 /*
  * Registers the ACL keyword list <kwl> as a list of valid keywords for next
  * parsing sessions.