usb: ftdi-elan: remove variable err_count

Variable err_count is just being incremented and it's never used
anywhere else. The variable and the increment are redundant so
remove it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20221020130649.1546112-1-colin.i.king@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>