floats: remove unnecessary transmute

Thanks @le-jzr!
diff --git a/src/lib.rs b/src/lib.rs
index 3740f64..7b86779 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1172,7 +1172,7 @@
         // NaNs differently. Therefore, to be safe, we pass a known quiet
         // NaN if u is any kind of NaN. The check above only assumes
         // IEEE 754-1985 to be valid.
-        unsafe { transmute(NAN) }
+        NAN
     } else {
         unsafe { transmute(u) }
     }
@@ -1191,7 +1191,7 @@
         // NaNs differently. Therefore, to be safe, we pass a known quiet
         // NaN if u is any kind of NaN. The check above only assumes
         // IEEE 754-1985 to be valid.
-        unsafe { transmute(NAN) }
+        NAN
     } else {
         unsafe { transmute(u) }
     }