caif: spi: missing platform_driver_unregister() on error in cfspi_init_module()

Add the missing platform_driver_unregister() before return
from cfspi_init_module() in the error handling case.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/caif/caif_spi.c b/drivers/net/caif/caif_spi.c
index b71ce9b..ae7e756 100644
--- a/drivers/net/caif/caif_spi.c
+++ b/drivers/net/caif/caif_spi.c
@@ -864,6 +864,7 @@
 	driver_remove_file(&cfspi_spi_driver.driver,
 			   &driver_attr_up_head_align);
  err_create_up_head_align:
+	platform_driver_unregister(&cfspi_spi_driver);
  err_dev_register:
 	return result;
 }