Input: synaptics - do not mix logical and bitwise operations

Let's stop using !!x to reduce value of trackstick button expression to 0/1
and use shift instead. This removes the following sparse warning:

  CHECK   drivers/input/mouse/synaptics.c
drivers/input/mouse/synaptics.c:943:79: warning: dubious: !x | y

Also, the bits we are testing are not capabilities, so lets drop "_CAP"
suffix from macro names.
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/synaptics.c

@@ -884,9 +884,9 @@ static void synaptics_report_ext_buttons(struct psmouse *psmouse,
 		u8 pt_buttons;
 
 		/* The trackstick expects at most 3 buttons */
-		pt_buttons = SYN_CAP_EXT_BUTTON_STICK_L(hw->ext_buttons)      |
-			     SYN_CAP_EXT_BUTTON_STICK_R(hw->ext_buttons) << 1 |
-			     SYN_CAP_EXT_BUTTON_STICK_M(hw->ext_buttons) << 2;
+		pt_buttons = SYN_EXT_BUTTON_STICK_L(hw->ext_buttons)      |
+			     SYN_EXT_BUTTON_STICK_R(hw->ext_buttons) << 1 |
+			     SYN_EXT_BUTTON_STICK_M(hw->ext_buttons) << 2;
 
 		serio_interrupt(priv->pt_port,
 				PSMOUSE_OOB_EXTRA_BTNS, SERIO_OOB_DATA);

drivers/input/mouse/synaptics.h

@@ -111,9 +111,9 @@
 #define SYN_CAP_EXT_BUTTONS_STICK(ex10)	((ex10) & 0x010000)
 #define SYN_CAP_SECUREPAD(ex10)		((ex10) & 0x020000)
 
-#define SYN_CAP_EXT_BUTTON_STICK_L(eb)	(!!((eb) & 0x01))
-#define SYN_CAP_EXT_BUTTON_STICK_M(eb)	(!!((eb) & 0x02))
-#define SYN_CAP_EXT_BUTTON_STICK_R(eb)	(!!((eb) & 0x04))
+#define SYN_EXT_BUTTON_STICK_L(eb)	(((eb) & BIT(0)) >> 0)
+#define SYN_EXT_BUTTON_STICK_M(eb)	(((eb) & BIT(1)) >> 1)
+#define SYN_EXT_BUTTON_STICK_R(eb)	(((eb) & BIT(2)) >> 2)
 
 /* synaptics modes query bits */
 #define SYN_MODE_ABSOLUTE(m)		((m) & (1 << 7))