build_packages: dump unusable nobuildretry argument

The retries argument doesn't exist for emerge. Most likely a
remnant of parallel_emerge. Dump the argument.

BUG=None
TEST=build_packages --nobuildretry fails parsing arguments

Change-Id: I1f521a453dfc2df1bfb913dd957f7d1177818528
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/1983240
Tested-by: Alex Klein <saklein@chromium.org>
Reviewed-by: Chris McDonald <cjmcdonald@chromium.org>
Commit-Queue: Alex Klein <saklein@chromium.org>
diff --git a/build_packages b/build_packages
index 70cc2ba..e477a39 100755
--- a/build_packages
+++ b/build_packages
@@ -81,8 +81,6 @@
   "Build factory installer."
 DEFINE_boolean withtest "${FLAGS_TRUE}" \
   "Build packages required for testing."
-DEFINE_boolean buildretry "${FLAGS_TRUE}" \
-  "Retry failed packages."
 
 # The --reuse_pkgs_from_local_boards flag tells Portage to share binary
 # packages between boards that are built locally, so that the total time
@@ -199,10 +197,6 @@
   EMERGE_CMD+=( "--force-remote-binary=chromeos-base/chromeos-chrome" )
 fi
 
-if [[ "${FLAGS_buildretry}" -eq "${FLAGS_FALSE}" ]]; then
-  EMERGE_CMD+=( --retries=0 )
-fi
-
 EMERGE_CMD+=( ${EXTRA_BOARD_FLAGS} )
 
 if [[ "${FLAGS_usepkg}" -eq "${FLAGS_TRUE}" ||