drm/xe/xe_survivability: Add index bound check

Fix static analysis tool reported issue. Add index bound check before
accessing info array to prevent out of bound.

Fixes: f4e9fc9 ("drm/xe/xe_survivability: Redesign survivability mode")
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patch.msgid.link/20251219105224.871930-6-riana.tauro@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

Author: rtauro1895

drivers/gpu/drm/xe/xe_survivability_mode.c

@@ -251,10 +251,14 @@ static umode_t survivability_info_attrs_visible(struct kobject *kobj, struct att
 	struct xe_survivability *survivability = &xe->survivability;
 	u32 *info = survivability->info;
 
-	/* FDO mode is visible only when supported */
-	if (idx >= MAX_SCRATCH_REG && survivability->version >= 2)
+	/*
+	 * Last index in survivability_info_attrs is fdo mode and is applicable only in
+	 * version 2 of survivability mode
+	 */
+	if (idx == MAX_SCRATCH_REG && survivability->version >= 2)
 		return 0400;
-	else if (info[idx])
+
+	if (idx < MAX_SCRATCH_REG && info[idx])
 		return 0400;
 
 	return 0;