Consolidate bash version checks

There were two checks for bash version, the 2nd was superfluous; this
patch removes the duplicate checks, and shifts the bash version check to
being back after the "are we in bash" check.

Change-Id: I57ff8c1fedce80f739c06643d2976d2c1465db1b
Merge remote-tracking branch 'upstream/cm-10.1' into cm-10.1