ftp: remove a check for NULL(!)

... as it implies we need to check for that on all the other variable
references as well (as Coverity otherwise warns us for missing NULL
checks), and we're alredy making sure that the pointer is never NULL.
diff --git a/lib/ftp.c b/lib/ftp.c
index 1008c63..40c51ea 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -4273,16 +4273,17 @@
       the first condition in the if() right here, is there just in case
       someone decides to set path to NULL one day
    */
-    if(data->state.path &&
-       data->state.path[0] &&
-       (data->state.path[strlen(data->state.path) - 1] != '/') )
-      filename = data->state.path;  /* this is a full file path */
-      /*
+    if(path_to_use[0] &&
+       (path_to_use[strlen(path_to_use) - 1] != '/') )
+      filename = path_to_use;  /* this is a full file path */
+    /*
+      else {
         ftpc->file is not used anywhere other than for operations on a file.
         In other words, never for directory operations.
         So we can safely leave filename as NULL here and use it as a
         argument in dir/file decisions.
-      */
+      }
+    */
     break;
 
   case FTPFILE_SINGLECWD: