use sprintf arg style with warning

warning('tsgqc_GUI:tsg_nc', ...
'unknow type ''%s'' for ''%s'' attribute.\nCheck your %s file', ...
type, member, ncv.file);   

@tsg_nc/tsg_nc.m

@@ -138,8 +138,9 @@ for i=1:ncv.size
 
           % by default, display a warning and cast to char
           % ----------------------------------------------
-          warning('tsgqc_GUI:tsg_nc', [' unknow type: ' type ...
-            ' for ' member ' attribute. Check your ' ncv.file ' file ...']);   
+          warning('tsgqc_GUI:tsg_nc', ...
+            'unknow type ''%s'' for ''%s'' attribute.\nCheck your %s file', ...
+            type, member, ncv.file);   
           theStruct.(member) = value; 
           
       end