Fix a problem when user selects -a (auto run) but we encounter a file

missing on the system. Instead of passing it by, mm was prompting...
bad mm, no cookie!

Brought to my attention by the PR, but the fix needed to be tweaked to
handle the auto-install option as well.

PR:		misc/25731 Gilbert Gong <ggong@cal.alumni.berkeley.edu>

usr.sbin/mergemaster/mergemaster.sh

@@ -684,7 +684,22 @@ for COMPFILE in `find . -type f -size +0`; do
   # diff_loop function knows how to handle it.
   #
   if [ ! -e "${DESTDIR}${COMPFILE#.}" ]; then
-    diff_loop
+    case "${AUTO_RUN}" in
+      '')
+        diff_loop
+        ;;
+      *)
+        case "${AUTO_INSTALL}" in
+        '')
+          # If this is an auto run, make it official
+          echo "   *** ${COMPFILE} will remain for your consideration"
+          ;;
+        *)
+          diff_loop
+          ;;
+        esac
+        ;;
+    esac # Auto run test
     continue
   fi