have usbsd partion the new sd devices.

Reference: /n/atom/patch/applied2013/usbsdpart
Date: Fri Oct 11 21:00:45 CES 2013
Signed-off-by: quanstro@quanstr.net

--- /rc/bin/usbsd	Fri Oct 11 21:00:30 2013
+++ /rc/bin/usbsd	Fri Oct 11 21:00:30 2013
@@ -53,6 +53,11 @@
 			exit nodev
 		}
 		echo config switch on spec $name type loop/$d >/dev/sdctl
+		sdpath=/dev/sd$name^0
+		if(test -f $sdpath/data)
+			disk/fdisk -p $sdpath/data>$sdpath/ctl
+		if(test -f $sdpath/plan9)
+			disk/prep -p $sdpath/plan9>$sdpath/ctl
 	}
 	if not
 		echo $d does not exist >[2=1]