[scudo] Rename AllocatorRingBuffer into scudo:ring_buffer

To maintain the convention of Scudo names starting with "scudo:",
which is used by some tooling to categorize memory usage.

Reviewed By: Chia-hungDuan

Differential Revision: https://reviews.llvm.org/D157102

Author: fabio-d

compiler-rt/lib/scudo/standalone/combined.h

@@ -1496,7 +1496,7 @@ class Allocator {
         map(/*Addr=*/nullptr,
             roundUp(ringBufferSizeInBytes(AllocationRingBufferSize),
                     getPageSizeCached()),
-            "AllocatorRingBuffer"));
+            "scudo:ring_buffer"));
     auto *RingBuffer = reinterpret_cast<AllocationRingBuffer *>(RawRingBuffer);
     RingBuffer->Size = AllocationRingBufferSize;
     static_assert(sizeof(AllocationRingBuffer) %