style: format io::Error::new in cp and printf stdout_state for better readability

- Split arguments onto multiple lines in both cp.rs and printf.rs to improve code formatting and consistency. No functional changes.

Author: mattsu2020

src/uu/cp/src/cp.rs

@@ -123,7 +123,10 @@ mod stdout_state {
             }
             #[cfg(not(unix))]
             {
-                return Err(io::Error::new(io::ErrorKind::BrokenPipe, "stdout was closed"));
+                return Err(io::Error::new(
+                    io::ErrorKind::BrokenPipe,
+                    "stdout was closed",
+                ));
             }
         }
         Ok(())

src/uu/printf/src/printf.rs

@@ -99,7 +99,10 @@ mod stdout_state {
             }
             #[cfg(not(unix))]
             {
-                return Err(io::Error::new(io::ErrorKind::BrokenPipe, "stdout was closed"));
+                return Err(io::Error::new(
+                    io::ErrorKind::BrokenPipe,
+                    "stdout was closed",
+                ));
             }
         }
         Ok(())