The commit consumes the argument of a unsupported printf command.
Without the commit - a subsequent command uses the argument of the preceding
command, which may cause memory corruption or page faults for sequences using
string commands, e.g.
Genode::printf("%#x %s\n", 0x20, "Test");
'#' is not supported by Genode::printf. In this scenario a pagefault at
address 0x20 is caused.
Fixes#1701
9b21c88bc6