net: qca_framing: use u16 for frame offset

It doesn't make sense to use a signed variable for offset here, so
fix it up.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qualcomm/qca_framing.h

@@ -103,7 +103,7 @@ struct qcafrm_handle {
 	enum qcafrm_state state;
 
 	/* Offset in buffer (borrowed for length too) */
-	s16 offset;
+	u16 offset;
 
 	/* Frame length as kept by this module */
 	u16 len;