perf: Fix perf_aux_size() for greater-than 32-bit size

perf_buffer->aux_nr_pages uses a 32-bit type, so a cast is needed to
calculate a 64-bit size.

Fixes: 45bfb2e ("perf: Add AUX area to ring buffer for raw data streams")
Signed-off-by: Adrian Hunter <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: ahunter6

kernel/events/internal.h

@@ -128,7 +128,7 @@ static inline unsigned long perf_data_size(struct perf_buffer *rb)
 
 static inline unsigned long perf_aux_size(struct perf_buffer *rb)
 {
-	return rb->aux_nr_pages << PAGE_SHIFT;
+	return (unsigned long)rb->aux_nr_pages << PAGE_SHIFT;
 }
 
 #define __DEFINE_OUTPUT_COPY_BODY(advance_buf, memcpy_func, ...)	\