The local variable 'ret' can be removed:
  drivers/nfc/s3fwrn5/i2c.c:167:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
 static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id)
 {
        struct s3fwrn5_i2c_phy *phy = phy_id;
-       int ret = 0;
 
        if (!phy || !phy->ndev) {
                WARN_ON_ONCE(1);
        switch (phy->mode) {
        case S3FWRN5_MODE_NCI:
        case S3FWRN5_MODE_FW:
-               ret = s3fwrn5_i2c_read(phy);
+               s3fwrn5_i2c_read(phy);
                break;
        case S3FWRN5_MODE_COLD:
-               ret = -EREMOTEIO;
                break;
        }