extcon: sm5502: remove redundant assignment to variable cable_type

The variable cable_type is being initialized with a value that
is never read and is being re-assigned a little later on. The
assignment is redundant and hence can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>