usb: ftdi-elan: fix possible condition with no effect (if == else)

fix  below warning reported by coccicheck

./drivers/usb/misc/ftdi-elan.c:2026:11-13: WARNING: possible condition
with no effect (if == else)

Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>