partitions: Mount storage for MTP after wipe

Conditionally run Add_MTP_Storage() after wipe if:
1) is wiped successfully
2) is storage (already implemented)
3) mount succeeds

Previous to this commit, Add_MTP_Storage() was called before mounting
storage, which fails. Mounting storage right after wipe should not be
a problem since Update_System_Details() does it anyways (and doesn't
complain if already mounted).

Change-Id: I8a5a78d5ac9181f3a9464dfe6b77284458f9868b

partition.cpp

@@ -1224,10 +1224,10 @@ bool TWPartition::Wipe(string New_File_System) {
 		if (Has_Data_Media && recreate_media) {
 			Recreate_Media_Folder();
 		}
+		if (Is_Storage && Mount(false))
+			PartitionManager.Add_MTP_Storage(MTP_Storage_ID);
 	}
-	if (Is_Storage) {
-		PartitionManager.Add_MTP_Storage(MTP_Storage_ID);
-	}
+
 	return wiped;
 }