[syscall.inc] Fixing register order in _syscall

src/syscalls.inc

@@ -4,7 +4,7 @@ macro _syscall code,[arg] {
     common
       _reg equ r9
       _reg equ r8
-      _reg equ rcx
+      _reg equ r10
       _reg equ rdx
       _reg equ rsi
       _reg equ rdi