platform/x86: huawei-wmi: Fix a precision vs width printf bug

This was supposed to be precision "%.*s" instead of width "%*s".  It's
possible that this results in printing beyond the end of the string.

Fixes: a970b95345ab ("platform/x86: huawei-wmi: Add debugfs support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>