This fixes most of the simpler shellcheck errors in shellcheck 0.4.6.
There are still a few warnings left that weren't simple to fix or
would have required more testing before I was confident in them.
Change-Id: I79ab3614cc1d69d3dfe1e0374e930313f2011cbf
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: https://review.coreboot.org/27598
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
987d42da1d