Avoid using '#' format spec for X hex numbers.

Avoid using '#' format spec for X (uppercase) hex numbers, as it
results in output like "0XABCDEF" instead of "0xABCDEF".

src/xenia/base/filesystem_win.cc

@@ -126,7 +126,7 @@ class Win32FileHandle : public FileHandle {
     } else {
       if (GetLastError() == ERROR_NOACCESS) {
         XELOGW(
-            "Win32FileHandle::Read(..., {}, {:#X}, ...) returned "
+            "Win32FileHandle::Read(..., {}, 0x{:X}, ...) returned "
             "ERROR_NOACCESS. Read-only memory?",
             buffer, buffer_length);
       }