wifi: cw1200: Fix potential NULL dereference

A recent refactoring was identified by smatch to cause another potential NULL
dereference:

drivers/net/wireless/st/cw1200/cw1200_spi.c:440 cw1200_spi_disconnect() error: we previously assumed 'self' could be null (see line 433)

Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Fixes: 2719a9e ("wifi: cw1200: Convert to GPIO descriptors")
Signed-off-by: Linus Walleij <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: linusw

drivers/net/wireless/st/cw1200/cw1200_spi.c

@@ -442,8 +442,8 @@ static void cw1200_spi_disconnect(struct spi_device *func)
 			cw1200_core_release(self->core);
 			self->core = NULL;
 		}
+		cw1200_spi_off(self, dev_get_platdata(&func->dev));
 	}
-	cw1200_spi_off(self, dev_get_platdata(&func->dev));
 }
 
 static int __maybe_unused cw1200_spi_suspend(struct device *dev)