[LVStringPool] Remove incorrect std::move (NFCI)

"Value" is still used afterwards in the return value. In this case,
this doesn't actually make a difference because a move for a
primitive type is the same as a copy, so there is no actual
misbehavior. Still drop the std::move to make the code less
confusing.

Author: nikic

llvm/include/llvm/DebugInfo/LogicalView/Core/LVStringPool.h

@@ -60,7 +60,7 @@ class LVStringPool {
     if (isValidIndex(Index))
       return Index;
     size_t Value = Entries.size();
-    ValueType *Entry = ValueType::create(Key, Allocator, std::move(Value));
+    ValueType *Entry = ValueType::create(Key, Allocator, Value);
     StringTable.insert(Entry);
     Entries.push_back(Entry);
     return Value;