Fixed eat not waiting for device if adb server was not started

$(adb get-state) returned unexpected starting server message
causing the if statement to fail. Calling "adb start-server"
beforehand remedies that.

Patch Set 2:
$(adb get-state) returns 'unknown' if Clockwork recovery is running on the device
look for /sbin/recovery and 'pass' the state test
also
adb wait-for-device
will result in endless loop, replace with until loop using with get-state OR 'recovery' tests

Patch Set 3:
fix the initial adb state test, use AND instead of OR

Patch Set 4:
Rebased and prevent "device not found" message from spamming the screen by
redirecting error output to null

Change-Id: I2d41b8853567cde80bf7fc08b5e4f0ad5ba1fdf5
Signed-off-by: Firerat <firer4t@googlemail.com>