coresight: trbe: Prevent overflow in PERF_IDX2OFF()

Cast nr_pages to unsigned long to avoid overflow when handling large
AUX buffer sizes (>= 2 GiB).

Fixes: 3fbf7f011f ("coresight: sink: Add TRBE driver")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

drivers/hwtracing/coresight/coresight-trbe.c

@@ -23,7 +23,8 @@
 #include "coresight-self-hosted-trace.h"
 #include "coresight-trbe.h"
 
-#define PERF_IDX2OFF(idx, buf) ((idx) % ((buf)->nr_pages << PAGE_SHIFT))
+#define PERF_IDX2OFF(idx, buf) \
+	((idx) % ((unsigned long)(buf)->nr_pages << PAGE_SHIFT))
 
 /*
  * A padding packet that will help the user space tools