check disassembler address properly in GenericDebugger.Disassemble

- closes #3524

- the address was not checked on the first call
- the comparison needs to be >=, not >

src/BizHawk.Client.EmuHawk/tools/Debugger/GenericDebugger.Disassembler.cs

@@ -57,16 +57,17 @@ namespace BizHawk.Client.EmuHawk
 			int lineCount = DisassemblerView.RowCount * 6 + 2;
 
 			_disassemblyLines.Clear();
-			uint a = _currentDisassemblerAddress;
+			uint currentAddress = _currentDisassemblerAddress;
 			for (int i = 0; i <= lineCount; ++i)
 			{
-				string line = Disassembler.Disassemble(MemoryDomains.SystemBus, a, out var advance);
-				_disassemblyLines.Add(new DisasmOp(a, advance, line));
-				a += (uint)advance;
-				if (a > BusMaxValue)
+				if (currentAddress >= BusMaxValue)
 				{
 					break;
 				}
+
+				string line = Disassembler.Disassemble(MemoryDomains.SystemBus, currentAddress, out var advance);
+				_disassemblyLines.Add(new DisasmOp(currentAddress, advance, line));
+				currentAddress += (uint)advance;
 			}
 		}