tools/nolibc/stdio: Implement vprintf()

vprintf() is equivalent to vfprintf() to stdout so implement it as a simple
wrapper for the existing vfprintf(), allowing us to build kselftest.h.

Suggested-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Willy Tarreau <w@1wt.eu>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/include/nolibc/stdio.h

@@ -273,6 +273,12 @@ int vfprintf(FILE *stream, const char *fmt, va_list args)
 	return written;
 }
 
+static __attribute__((unused))
+int vprintf(const char *fmt, va_list args)
+{
+	return vfprintf(stdout, fmt, args);
+}
+
 static __attribute__((unused, format(printf, 2, 3)))
 int fprintf(FILE *stream, const char *fmt, ...)
 {