sanitizer_common: fix deadlock detector output

[dvyukov]

Summary

Print PC of the previous lock, not the current one.
The current one will be printed during unwind.

compiler-rt/lib/sanitizer_common/sanitizer_mutex.cpp

if (max_idx == type && mutex_multi[type]) {
       CHECK_EQ(locked[type].seq, max_seq);
       CHECK(locked[type].pc);
       locked[type].recursion++;
       return;
     }
     if (max_idx != MutexInvalid && !mutex_can_lock[max_idx][type]) {
       Printf("%s: internal deadlock: can't lock %s under %s mutex\n", SanitizerToolName,
              mutex_meta[type].name, mutex_meta[max_idx].name);
-      PrintMutexPC(pc);
+      PrintMutexPC(locked[max_idx].pc);
       CHECK(0);
     }
     locked[type].seq = ++sequence;
     locked[type].pc = pc;
     locked[type].recursion = 1;
   }
 
   void Unlock(MutexType type) {