split out winsize from sys_ioctl header

src/header/sys_ioctl/mod.rs

@@ -12,21 +12,6 @@ pub struct sgttyb {
     sg_flags: c_ushort,
 }
 
-#[repr(C)]
-#[derive(Default)]
-pub struct winsize {
-    ws_row: c_ushort,
-    ws_col: c_ushort,
-    ws_xpixel: c_ushort,
-    ws_ypixel: c_ushort,
-}
-
-impl winsize {
-    pub fn get_row_col(&self) -> (c_ushort, c_ushort) {
-        (self.ws_row, self.ws_col)
-    }
-}
-
 #[cfg(target_os = "linux")]
 pub use self::linux::*;