Fix clippy warnings

cursive-core/src/view/scroll/core.rs

@@ -618,7 +618,7 @@ impl Core {
             XY::zip4(Orientation::pair(), position, lengths, offsets)
                 .keep(grabbed.and(self.enabled))
                 .into_iter()
-                .filter_map(|x| x)
+                .flatten()
                 .next()
         {
             if pos >= offset && pos < offset + length {

cursive-core/src/xy.rs

@@ -3,6 +3,7 @@ use std::iter;
 
 /// A generic structure with a value for each axis.
 #[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Hash)]
+#[allow(clippy::upper_case_acronyms)]
 pub struct XY<T> {
     /// X-axis value
     pub x: T,