drm/exynos: fix a timeout loop

We were trying to print an error message if we timed out here, but the
loop actually ends with "tries" set to UINT_MAX and not zero.  Fix this
by changing from tries-- to --tries.

A for loop would actually be the most natural way to do this.  My fix
means we only loop 99 times instead of 100 but that's probably ok.

Fixes: a696394c5224 ('drm/exynos: mixer: simplify loop in vp_win_reset()')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Tobias Jakobi <tjakobi@math.uni-bielefeld.de>
Signed-off-by: Inki Dae <inki.dae@samsung.com>

drivers/gpu/drm/exynos/exynos_mixer.c

@@ -701,7 +701,7 @@ static void vp_win_reset(struct mixer_context *ctx)
 	unsigned int tries = 100;
 
 	vp_reg_write(res, VP_SRESET, VP_SRESET_PROCESSING);
-	while (tries--) {
+	while (--tries) {
 		/* waiting until VP_SRESET_PROCESSING is 0 */
 		if (~vp_reg_read(res, VP_SRESET) & VP_SRESET_PROCESSING)
 			break;