Merge 98292 - Show only one error notification per inserted mulitpartitioned usb card.

Merge 98292 - Show only one error notification per inserted mulitpartitioned usb card.

iWe should use system path of the device that contains partitions block device, instead partitions system path as notifications identification path.

e.g.
/sys/devices/pci0000:00/0000:00:1d.7/usb1/1-6/1-6:1.0/host9/target9:0:0/9:0:0:0
instead of
/sys/devices/pci0000:00/0000:00:1d.7/usb1/1-6/1-6:1.0/host9/target9:0:0/9:0:0:0/block/sdb/sdb9

TEST=Manual on Cr48 (tried multiple-partitioned device with no good partitions, with one good-partition, device with one partition)
BUG=chromium-os:19559
Review URL: http://codereview.chromium.org/7748003

TBR=tbarzic@chromium.org
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=98838