use casts instead of transmute in mino::Mat::new()

mino/src/matrix.rs

@@ -34,7 +34,7 @@ impl Mat {
         if data.len() >= i16::MAX as usize {
             panic!("matrix height overflows i16");
         }
-        unsafe { core::mem::transmute(data) }
+        unsafe { &*(data as *const [u16] as *const Self) }
     }
 
     pub const EMPTY: &'static Self = Self::new(&[]);