drm/etnaviv: fix some off by one bugs

The ->nr_signal is the supposed to be the number of elements in the
->signal array.  There was one place where it was 5 but it was supposed
to be 4.  That looks like a copy and paste bug.  There were also two
checks that were off by one.

Fixes: 9e2c2e27 ("drm/etnaviv: add infrastructure to query perf counter")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Tested-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_perfmon.c

@@ -113,7 +113,7 @@ static const struct etnaviv_pm_domain doms_3d[] = {
 		.name = "PE",
 		.profile_read = VIVS_MC_PROFILE_PE_READ,
 		.profile_config = VIVS_MC_PROFILE_CONFIG0,
-		.nr_signals = 5,
+		.nr_signals = 4,
 		.signal = (const struct etnaviv_pm_signal[]) {
 			{
 				"PIXEL_COUNT_KILLED_BY_COLOR_PIPE",
@@ -435,7 +435,7 @@ int etnaviv_pm_query_sig(struct etnaviv_gpu *gpu,
 
 	dom = meta->domains + signal->domain;
 
-	if (signal->iter > dom->nr_signals)
+	if (signal->iter >= dom->nr_signals)
 		return -EINVAL;
 
 	sig = &dom->signal[signal->iter];
@@ -461,7 +461,7 @@ int etnaviv_pm_req_validate(const struct drm_etnaviv_gem_submit_pmr *r,
 
 	dom = meta->domains + r->domain;
 
-	if (r->signal > dom->nr_signals)
+	if (r->signal >= dom->nr_signals)
 		return -EINVAL;
 
 	return 0;