SymbolDB: Only match against the function name

This changes GetSymbolFromName to not require the passed name to
completely match with the symbol name. Instead, we now match
against the stripped symbol name (i.e. only the function name).

This fixes a regression introduced by #4160, which prevented
HLE::PatchFunctions() from working properly.

Source/Core/Common/SymbolDB.h

@@ -30,6 +30,7 @@ struct Symbol
   };
 
   std::string name;
+  std::string function_name;   // stripped function name
   std::vector<SCall> callers;  // addresses of functions that call this function
   std::vector<SCall> calls;    // addresses of functions that are called by this function
   u32 hash = 0;                // use for HLE function finding