Remove sbi_printk macro

pk/sbi_impl.c

@@ -5,12 +5,6 @@
 #include "mcall.h"
 #include <errno.h>
 
-#define sbi_printk(str, ...) ({ \
-  char buf[1024]; /* XXX */ \
-  sprintk(buf, str, __VA_ARGS__); \
-  for (size_t i = 0; buf[i]; i++) \
-    do_mcall(MCALL_CONSOLE_PUTCHAR, buf[i]); })
-
 uintptr_t __sbi_query_memory(uintptr_t id, memory_block_info *p)
 {
   if (id == 0) {