Revert "Use --fast by default in build_image when --jobs is enabled."

This reverts commit f0fb864e8df91551daeb3a10a650c6f4751425ca.

This change needs to be reverted because it suppresses logging output
from the build process.  Thus, when something goes wrong...the
sherriff is left completely helpless in terms of debugging the issue.

TBR: davidjames@chromium.org

build_image

@@ -92,11 +92,6 @@ if [ "${FLAGS_rootfs_size}" -gt "${FLAGS_rootfs_partition_size}" ] ; then
   exit 1
 fi
 
-if [ ${FLAGS_jobs} -ne -1 ]; then
-  EMERGE_JOBS="--jobs=${FLAGS_jobs}"
-  FLAGS_fast=${FLAGS_TRUE}
-fi
-
 EMERGE_BOARD_CMD="emerge-${FLAGS_board}"
 if [ "${FLAGS_fast}" -eq "${FLAGS_TRUE}" ]; then
   echo "Using alternate emerge"
@@ -166,6 +161,10 @@ if [[ ${FLAGS_factory_install} -eq ${FLAGS_TRUE} ]] ; then
   INSTALL_MASK="${INSTALL_MASK} ${FACTORY_INSTALL_MASK}"
 fi
 
+if [[ ${FLAGS_jobs} -ne -1 ]]; then
+  EMERGE_JOBS="--jobs=${FLAGS_jobs}"
+fi
+
 # Figure out ARCH from the given toolchain.
 # TODO: Move to common.sh as a function after scripts are switched over.
 TC_ARCH=$(echo "${CHOST}" | awk -F'-' '{ print $1 }')

common.sh

@@ -325,13 +325,14 @@ function die {
 }
 
 # Retry an emerge command according to $FLAGS_retries
+# The $EMERGE_JOBS flags will only be added the first time the command is run
 function eretry () {
-  $* && return 0
   local i=
   for i in $(seq $FLAGS_retries); do
     echo Retrying $*
-    $* && return 0
+    $* $EMERGE_JOBS && return 0
   done
+  $* && return 0
   return 1
 }