fix up datamedia volume detection
fix up datamedia volume detection

Change-Id: Ia853e31e31aebce9e70b1e9500930b14a92ee4bf

InsomniaAOSP/platform_bootable_recovery,76Demented/bootable_recovery-,Plain-Andy/android_platform_bootable_recovery,kylinmoddev/android_bootable_recovery,DerTeufel/dualboot_recovery,InsomniaAOSP/platform_bootable_recovery,76Demented/bootable_recovery-,DerTeufel/dualboot_recovery,InsomniaAOSP/platform_bootable_recovery,Plain-Andy/android_platform_bootable_recovery,76Demented/bootable_recovery-,randomblame/bootable_recovery,DerTeufel/dualboot_recovery,kylinmoddev/android_bootable_recovery,DerTeufel/dualboot_recovery,randomblame/bootable_recovery,randomblame/bootable_recovery,Plain-Andy/android_platform_bootable_recovery,76Demented/bootable_recovery-,76Demented/bootable_recovery-,InsomniaAOSP/platform_bootable_recovery,randomblame/bootable_recovery,Plain-Andy/android_platform_bootable_recovery,kylinmoddev/android_bootable_recovery,kylinmoddev/android_bootable_recovery,InsomniaAOSP/platform_bootable_recovery,randomblame/bootable_recovery,DerTeufel/dualboot_recovery