usb: yurex: Fix inconsistent locking bug in yurex_read()

Unlock before returning on the error path.

Fixes: 86b20af1

 ("usb: yurex: Replace snprintf() with the safer scnprintf() variant")
Reported-by: Dan Carpenter <error27@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202312170252.3udgrIcP-lkp@intel.com/
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Link: https://lore.kernel.org/r/20231219063639.450994-1-harshit.m.mogalapalli@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>