nfc: st21nfca: remove redundant assignment to variable i

nfc: st21nfca: remove redundant assignment to variable i

Variable i is being assigned a value that is never read, the
assignment is redundant and can be removed. Cleans up clang-scan
build warning:

drivers/nfc/st21nfca/i2c.c:319:4: warning: Value stored to 'i'
is never read [deadcode.DeadStores]
                        i = 0;

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211230161230.428457-1-colin.i.king@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>