[m-rev.] diff: Change git submodule update command in prepare.sh.

[Peter Wang]

prepare.sh:
    Don't pass --remote to the 'git submodule update'.
    We want the boehm_gc submodule to be checked out at the commit
    recorded in the mercury repository, not automatically update to the
    latest commit on the branch listed in .gitmodules. Similarly for
    libatomic_ops within the boehm_gc submodule.

    Fix help message.
---
 prepare.sh | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/prepare.sh b/prepare.sh
index 2ca5c05db..55ebc2654 100755
--- a/prepare.sh
+++ b/prepare.sh
@@ -1,15 +1,16 @@
-#!/bin/sh -e
+#!/bin/sh
 # This script should be run in a fresh git checkout in order to initialise
 # the necessary git submodules and produce the configure script.
+set -e
 
 if [ ! -e boehm_gc/.git ]; then
     echo "Setting up submodules"
     if git submodule --quiet init; then
-        git submodule update --remote --init --recursive
+        git submodule update --init --recursive
     else
-        echo "There was a problem configuring the submodules.  If the"
-        echo "repositories could not be found then edit .git/config and run"
-        echo "get submodule update"
+        echo "There was a problem configuring the submodules."
+        echo "If the repositories could not be found then edit .gitmodules"
+        echo "then run: git submodule update --recursive"
         exit 1
     fi
 fi
-- 
2.39.0