ipq807x: silence dd errors in do_flash_emmc

Running dd if=/dev/zero to a partition will always throw an ENOSPC error
when reaching the end of the partition. Silence those errors to avoid
confusion.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>

feeds/ipq807x/ipq807x/base-files/lib/upgrade/platform.sh

@@ -44,7 +44,7 @@ do_flash_emmc() {
 	}
 
 	echo erase $4
-	dd if=/dev/zero of=${emmcblock}
+	dd if=/dev/zero of=${emmcblock} 2> /dev/null
 	echo flash $4
 	tar Oxf $tar_file ${board_dir}/$part | dd of=${emmcblock}
 }