Split out the non-ARM specific portions of SYS_WRITE to a
reusable function. This handles all GuestFD. This removes
the last use of common_semi_syscall_len.
Note that gdb_do_syscall %x reads target_ulong, not int.
Reviewed-by: Luc Michel <lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
aa915bd0a6