ota_from_target_files: remove duplicate setting of recovery_img

This variable is already set earlier in the script and does not need
to be wrapped inside of the if statement

Change-Id: I91b7f7d2fc911a3910b3df09cff0ca0f44fe7741
Merge pull request #6 from CyanogenMod/cm-11.0

ota_from_target_files: remove duplicate setting of recovery_img