drivers/sbus/char: Micro-optimization in display7seg.c

Flipping a bit doesn't need four lines of code; and gcc seems to
actually generate two branches.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/sbus/char/display7seg.c b/drivers/sbus/char/display7seg.c
index b48899c..2b0ce7c 100644
--- a/drivers/sbus/char/display7seg.c
+++ b/drivers/sbus/char/display7seg.c
@@ -144,10 +144,7 @@
 
 	case D7SIOCTM:
 		/* toggle device mode-- flip display orientation */
-		if (regs & D7S_FLIP)
-			regs &= ~D7S_FLIP;
-		else
-			regs |= D7S_FLIP;
+		regs ^= D7S_FLIP;
 		writeb(regs, p->regs);
 		break;
 	}