[HWASAN] Remove GetRequestedSize check from Metadata::IsAllocated

[kstoimenov]

Summary

After D143438 there is no point in this check as the size will never 0. Also this keeps it consistent with ASAN where there is not size check in LsanMetadata::allocated.

compiler-rt/lib/hwasan/hwasan_allocator.cpp

 inline void Metadata::SetUnallocated() {
   atomic_store(&chunk_state, CHUNK_INVALID, memory_order_release);
   requested_size_low = 0;
   requested_size_high = 0;
   atomic_store(&alloc_context_id, 0, memory_order_relaxed);
 }
 
 inline bool Metadata::IsAllocated() const {
-  return atomic_load(&chunk_state, memory_order_relaxed) == CHUNK_ALLOCATED &&
-         GetRequestedSize();
+  return atomic_load(&chunk_state, memory_order_relaxed) == CHUNK_ALLOCATED;
 }
 
 inline u64 Metadata::GetRequestedSize() const {
   return (static_cast<u64>(requested_size_high) << 32) + requested_size_low;
 }
 
 inline u32 Metadata::GetAllocStackId() const {
   return atomic_load(&alloc_context_id, memory_order_relaxed);