mfd: wm8350 tries reaches -1

With a postfix decrement tries will reach -1 rather than 0,
so the warning will not be issued even upon timeout.

Signed-off-by: Roel Kluin <[e-mail]>
Acked-by: Mark Brown <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/wm8350-core.c

···
 	do {
 		schedule_timeout_interruptible(1);
 		reg = wm8350_reg_read(wm8350, WM8350_DIGITISER_CONTROL_1);
-	} while (tries-- && (reg & WM8350_AUXADC_POLL));
+	} while (--tries && (reg & WM8350_AUXADC_POLL));
 
 	if (!tries)
 		dev_err(wm8350->dev, "adc chn %d read timeout\n", channel);