sign_official_build: Fix shellcheck echo lints

Fix all instances of "SC2005 (style): Useless echo? Instead of 'echo
$(cmd)', just use 'cmd'."

BRANCH=none
BUG=None
TEST=cros lint scripts/image_signing/sign_official_build.sh
TEST=scripts/image_signing/sign_official_build.sh recovery \
TEST=  ~/chromiumos/src/build/images/reven/latest/chromiumos_image.bin
TEST=  tests/devkeys
TEST=  ~/chromiumos/src/build/images/reven/latest/chromiumos_image.signed

Change-Id: Ia11a30187cb79077aeee4c626dc41de9bee5a12b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4245619
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/4380984
Tested-by: Phoebe Wang <phoebewang@chromium.org>
Reviewed-by: Cheng Yueh <cyueh@chromium.org>
Commit-Queue: Cheng Yueh <cyueh@chromium.org>
Auto-Submit: Phoebe Wang <phoebewang@chromium.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/scripts/image_signing/sign_official_build.sh b/scripts/image_signing/sign_official_build.sh
index e063cdad..a5945433 100755
--- a/scripts/image_signing/sign_official_build.sh
+++ b/scripts/image_signing/sign_official_build.sh
@@ -114,7 +114,7 @@ get_hash_from_config() {
   dm_config=$(get_dmparams_from_config "${kernel_config}")
   local vroot_dev
   vroot_dev=$(get_dm_device "${dm_config}" vroot)
-  echo $(get_verity_arg "${vroot_dev}" root_hexdigest)
+  get_verity_arg "${vroot_dev}" root_hexdigest
 }
 
 # Get the mapped device and its args.
@@ -124,7 +124,7 @@ get_hash_from_config() {
 get_dm_device() {
   local dm=$1
   local device=$2
-  echo $(echo "${dm}" | sed -nre "s/.*${device}[^,]*,([^,]*).*/\1/p")
+  echo "${dm}" | sed -nre "s/.*${device}[^,]*,([^,]*).*/\1/p"
 }
 
 # Set the mapped device and its args for a device.
@@ -135,8 +135,7 @@ set_dm_device() {
   local dm=$1
   local device=$2
   local args=$3
-  echo $(echo "${dm}" |
-    sed -nre "s#(.*${device}[^,]*,)([^,]*)(.*)#\1${args}\3#p")
+  echo "${dm}" | sed -nre "s#(.*${device}[^,]*,)([^,]*)(.*)#\1${args}\3#p"
 }
 
 CALCULATED_KERNEL_CONFIG=