SystemInformation: fix calling kwsysProcess_WaitForData()
SystemInformation: fix calling kwsysProcess_WaitForData()

kwsysProcess_WaitForData() may return kwsysProcess_Pipe_Timeout, which
is 255. The current check would take that as sign of success and read
invalid data or even crash.

Change-Id: I148f5d435a088cb3814f513cce4f13e5358e5730

chuckatkins/KWSys,chuckatkins/KWSys,chuckatkins/KWSys,chuckatkins/KWSys