HID: uhid: use strlcpy() instead of strncpy()

gcc-8 reports

drivers/hid/uhid.c: In function 'uhid_dev_create2':
./include/linux/string.h:245:9: warning: '__builtin_strncpy' output may
be truncated copying 127 bytes from a string of length 127
[-Wstringop-truncation]

The compiler require that the input param 'len' of strncpy() should be
greater than the length of the src string, so that '\0' is copied as
well. We can just use strlcpy() to avoid this warning.

Signed-off-by: Xiongfeng Wang <xiongfeng.wang@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>