mmc: moxart: remove unneeded check for drvdata

The 'struct mmc_host *mmc' comes from drvdata set at the end of probe,
so it cannot be NULL.  The code already dereferences it few lines before
the check with mmc_priv().  This also fixes smatch warning:

  drivers/mmc/host/moxart-mmc.c:692 moxart_remove() warn: variable dereferenced before check 'mmc' (see line 688)
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200923153739.30327-1-krzk@kernel.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/moxart-mmc.c

@@ -689,19 +689,18 @@ static int moxart_remove(struct platform_device *pdev)
 
 	dev_set_drvdata(&pdev->dev, NULL);
 
-	if (mmc) {
-		if (!IS_ERR(host->dma_chan_tx))
-			dma_release_channel(host->dma_chan_tx);
-		if (!IS_ERR(host->dma_chan_rx))
-			dma_release_channel(host->dma_chan_rx);
-		mmc_remove_host(mmc);
-		mmc_free_host(mmc);
+	if (!IS_ERR(host->dma_chan_tx))
+		dma_release_channel(host->dma_chan_tx);
+	if (!IS_ERR(host->dma_chan_rx))
+		dma_release_channel(host->dma_chan_rx);
+	mmc_remove_host(mmc);
+	mmc_free_host(mmc);
+
+	writel(0, host->base + REG_INTERRUPT_MASK);
+	writel(0, host->base + REG_POWER_CONTROL);
+	writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
+	       host->base + REG_CLOCK_CONTROL);
 
-		writel(0, host->base + REG_INTERRUPT_MASK);
-		writel(0, host->base + REG_POWER_CONTROL);
-		writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF,
-		       host->base + REG_CLOCK_CONTROL);
-	}
 	return 0;
 }