usb: gadget: f_uac2: remove redundant assignments to pointer i_feature

usb: gadget: f_uac2: remove redundant assignments to pointer i_feature

Pointer i_feature is being initialized with a value and then immediately
re-assigned a new value in the next statement. Fix this by replacing the
the redundant initialization with the following assigned value.

Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210804125907.111654-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>