x86/decoder: Use stderr if insn sanity test fails

If the instruction sanity test fails, it prints a "Failure" message to
stdout. Make this program behave like the rest of the build and print
that message to stderr.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1477428965-20548-3-git-send-email-pebolle@tiscali.nl
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/tools/insn_sanity.c

@@ -269,7 +269,8 @@ int main(int argc, char **argv)
 		insns++;
 	}
 
-	fprintf(stdout, "%s: %s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n",
+	fprintf((errors) ? stderr : stdout,
+		"%s: %s: decoded and checked %d %s instructions with %d errors (seed:0x%x)\n",
 		prog,
 		(errors) ? "Failure" : "Success",
 		insns,