Fix is_done() always returns true

Author: kalkyl

nrf-hal-common/src/twis.rs

@@ -518,8 +518,7 @@ impl<T: Instance, B> Transfer<T, B> {
             .inner
             .as_mut()
             .unwrap_or_else(|| unsafe { core::hint::unreachable_unchecked() });
-        inner.twis.is_done();
-        true
+        inner.twis.is_done()
     }
 }
 
@@ -561,4 +560,4 @@ mod _twis1 {
     impl Instance for TWIS1 {
         const INTERRUPT: Interrupt = Interrupt::SPIM1_SPIS1_TWIM1_TWIS1_SPI1_TWI1;
     }
-}
+}