Fix printf formats

src/ia32/disasm-ia32.cc

Index: src/ia32/disasm-ia32.cc
diff --git a/src/ia32/disasm-ia32.cc b/src/ia32/disasm-ia32.cc
index 3cd0ac6e52fbe9d20e85faf60311971b80b18488..274903ba455ee221dc1b5c63042fe76e429fe5de 100644
--- a/src/ia32/disasm-ia32.cc
+++ b/src/ia32/disasm-ia32.cc
@@ -8,6 +8,7 @@
 
 #if V8_TARGET_ARCH_IA32
 
+#include "src/base/compiler-specific.h"
 #include "src/disasm.h"
 
 namespace disasm {
@@ -389,8 +390,7 @@ class DisassemblerIA32 {
   int MemoryFPUInstruction(int escape_opcode, int regop, byte* modrm_start);
   int RegisterFPUInstruction(int escape_opcode, byte modrm_byte);
   int AVXInstruction(byte* data);
-  void AppendToBuffer(const char* format, ...);
-
+  PRINTF_FORMAT(2, 3) void AppendToBuffer(const char* format, ...);
 
   void UnimplementedInstruction() {
     if (abort_on_unimplemented_) {
@@ -1274,7 +1274,7 @@ int DisassemblerIA32::InstructionDecode(v8::internal::Vector<char> out_buffer,
     const InstructionDesc& idesc = instruction_table_->Get(*data);
     switch (idesc.type) {
       case ZERO_OPERANDS_INSTR:
-        AppendToBuffer(idesc.mnem);
+        AppendToBuffer("%s", idesc.mnem);
         data++;
         break;