msc: split off f_mgcp_find_param_entry()

Split f_mgcp_find_param_entry() out of f_mgcp_find_param() to be able to act on
an MgcpParameterList without an enclosing MgcpMessage.

Will be used by upcoming I8b82476f55a98f7a94d5c4f1cd80eac427b2d20f

Change-Id: I90f213d2a1be979afa024e0faa25d532f9858636
diff --git a/library/MGCP_Templates.ttcn b/library/MGCP_Templates.ttcn
index dae379e..e03fd8e 100644
--- a/library/MGCP_Templates.ttcn
+++ b/library/MGCP_Templates.ttcn
@@ -453,6 +453,17 @@
 		sdp := *
 	}
 
+	function f_mgcp_find_param_entry(MgcpParameterList pars, MgcpInfoCode code, out charstring ret)
+	return boolean {
+		for (var integer i := 0; i < sizeof(pars); i := i+1) {
+			if (pars[i].code == code) {
+				ret := pars[i].val;
+				return true;
+			}
+		}
+		return false;
+	}
+
 	function f_mgcp_find_param(MgcpMessage msg, MgcpInfoCode code, out charstring ret)
 	return boolean {
 		var MgcpParameterList pars;
@@ -461,13 +472,7 @@
 		} else {
 			pars := msg.response.params;
 		}
-		for (var integer i := 0; i < sizeof(pars); i := i+1) {
-			if (pars[i].code == code) {
-				ret := pars[i].val;
-				return true;
-			}
-		}
-		return false;
+		return f_mgcp_find_param_entry(pars, code, ret);
 	}
 
 	/* template to determine if a MGCP endpoint is a wildcard endpoint */