bin/xzoomscr: Add missing `$' in arithmetic.

POSIX requires this, though shells commonly don't.

diff --git a/bin/xzoomscr b/bin/xzoomscr
index f852297..6add5fa 100755 (executable)
--- a/bin/xzoomscr
+++ b/bin/xzoomscr
@@ -17,7 +17,7 @@ DISPLAY=$dpybase.$scr; export DISPLAY
 
 eval $(xscsize -b)
 
-case $(( $XWIDTH % $zoom || XHEIGHT % $zoom )) in
+case $(( $XWIDTH % $zoom || $XHEIGHT % $zoom )) in
   0) ;;
   *) echo >&2 "$0: zoom multiplier doesn't divide screen size"; exit 2 ;;
 esac