autobuild: Factor out HOSTNAME variable.

autobuild.sh

@@ -2,18 +2,19 @@
 
 PROJECT=febootstrap
 MAILTO=libguestfs@redhat.com
+HOSTNAME="$(hostname -s)"
 
 #----------------------------------------------------------------------
 # Helper functions.
 
 failed ()
 {
-    mail -s "$(hostname -s) $PROJECT FAILED $1 $gitsha" $MAILTO < local-log
+    mail -s "$HOSTNAME $PROJECT FAILED $1 $gitsha" $MAILTO < local-log
 }
 
 ok ()
 {
-    mail -s "$(hostname -s) $PROJECT success $gitsha" $MAILTO < local-log
+    mail -s "$HOSTNAME $PROJECT success $gitsha" $MAILTO < local-log
 }
 
 #----------------------------------------------------------------------
@@ -25,7 +26,7 @@ rm -f local-log
 cat > local-log <<EOF
 
 This is an automatic message generated by the builder on
-$(hostname -s) for $PROJECT.  Log files from the build
+$HOSTNAME for $PROJECT.  Log files from the build
 follow below.
 
 $(uname -a)