drm/amd/powerplay: Fix an off by one in navi10_get_smu_msg_index()

The navi10_message_map[] array has SMU_MSG_MAX_COUNT elements so the ">"
has to be changed to ">=" to prevent reading one element beyond the end
of the array.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/navi10_ppt.c

@@ -213,7 +213,7 @@ static int navi10_get_smu_msg_index(struct smu_context *smc, uint32_t index)
 {
 	struct smu_11_0_cmn2aisc_mapping mapping;
 
-	if (index > SMU_MSG_MAX_COUNT)
+	if (index >= SMU_MSG_MAX_COUNT)
 		return -EINVAL;
 
 	mapping = navi10_message_map[index];