submodule: show full path in error message

When --recursive was added to "submodule foreach" in commit 15fc56a (git
submodule foreach: Add --recursive to recurse into nested submodules,
2009-08-19), the error message when the script returns a non-zero status
was not updated to contain $prefix to show the full path.  Fix this.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-submodule.sh

@@ -485,7 +485,7 @@ cmd_foreach()
 					cmd_foreach "--recursive" "$@"
 				fi
 			) <&3 3<&- ||
-			die "$(eval_gettext "Stopping at '\$sm_path'; script returned non-zero status.")"
+			die "$(eval_gettext "Stopping at '\$prefix\$sm_path'; script returned non-zero status.")"
 		fi
 	done
 }