mmdevapi: Fix buffer overflow in pulse_set_sample_rate.

(cherry picked from commit 6170680)

Cw-Bug-Id: #24327
(cherry picked from commit 7f3e7a6)

Author: tati-frog

dlls/winepulse.drv/pulse.c

@@ -2573,7 +2573,7 @@ static NTSTATUS pulse_set_sample_rate(void *args)
     size = 0;
     NtFreeVirtualMemory(GetCurrentProcess(), (void **)&stream->local_buffer, &size, MEM_RELEASE);
 
-    silence_buffer(new_ss.format, new_buffer, size);
+    silence_buffer(new_ss.format, new_buffer, stream->real_bufsize_bytes);
     stream->local_buffer = new_buffer;
 
 exit: