Recovery: remove wiping of res folder

The rm -rf of the res folder wipes out all of the TWRP theme and
images. Remove this so that TWRP will work properly.

Change-Id: I27c372d53eaae3cc8b476a909c2d3f3fc4fcb558
Merge "Recovery: remove wiping of res folder" into lp5.0
Merge remote-tracking branch 'slim/lp5.0' into lp50s-test