f_rmnet: Don't register for already registerd SMD platform driver

currently, USB driver is registering for platform driver that is
already registered. Avoid this multiple registrations.

CRs-fixed: 403650
Change-Id: I4446f00a5634e4c1146b84381da063284aeed6c9
Signed-off-by: Chiranjeevi Velempati <cvelempa@codeaurora.org>
diff --git a/drivers/usb/gadget/f_rmnet_smd.c b/drivers/usb/gadget/f_rmnet_smd.c
index b71f646..5e2c6ed 100644
--- a/drivers/usb/gadget/f_rmnet_smd.c
+++ b/drivers/usb/gadget/f_rmnet_smd.c
@@ -907,13 +907,14 @@
 		 * Register platform driver to be notified in case SMD channels
 		 * later becomes ready to be opened.
 		 */
-		ret = platform_driver_register(&dev->pdrv);
-		if (ret)
-			ERROR(cdev, "Platform driver %s register failed %d\n",
-					dev->pdrv.driver.name, ret);
-		else
-			dev->is_pdrv_used = 1;
-
+		if (!dev->is_pdrv_used) {
+			ret = platform_driver_register(&dev->pdrv);
+			if (ret)
+				ERROR(cdev, "pdrv %s register failed %d\n",
+						dev->pdrv.driver.name, ret);
+			else
+				dev->is_pdrv_used = 1;
+		}
 		return;
 	}
 	wait_event(dev->smd_ctl.wait, test_bit(CH_OPENED,