PPCSymbolDB: Drop useless const qualifier

Source/Core/Core/PowerPC/PPCSymbolDB.cpp

@@ -112,7 +112,7 @@ Symbol* PPCSymbolDB::GetSymbolFromAddr(u32 addr)
   return nullptr;
 }
 
-const std::string PPCSymbolDB::GetDescription(u32 addr)
+std::string PPCSymbolDB::GetDescription(u32 addr)
 {
   Symbol* symbol = GetSymbolFromAddr(addr);
   if (symbol)

Source/Core/Core/PowerPC/PPCSymbolDB.h

@@ -31,7 +31,7 @@ public:
 
   Symbol* GetSymbolFromAddr(u32 addr) override;
 
-  const std::string GetDescription(u32 addr);
+  std::string GetDescription(u32 addr);
 
   void FillInCallers();