run_rc_command - don't prefix the rcvar variable name with the dollar sign.

The output without the dollar sign is less confusing as it's actual
valid shell syntax:

  $ /etc/rc.d/foo rcvar
  # food
  food=YES

Brought up on tech-userlevel@ by Rocky Hotas with some LGTMs from
other people and no objections.

We still refer to '$food' in warnings/errors though.

etc/rc.subr

@@ -1,4 +1,4 @@
-# $NetBSD: rc.subr,v 1.105 2020/09/17 20:29:03 otis Exp $
+# $NetBSD: rc.subr,v 1.106 2020/12/20 21:30:28 uwe Exp $
 #
 # Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -822,9 +822,9 @@ $command $rc_flags $command_args"
 			echo "# $name"
 			if [ -n "$rcvar" ]; then
 				if checkyesno ${rcvar}; then
-					echo "\$${rcvar}=YES"
+					echo "${rcvar}=YES"
 				else
-					echo "\$${rcvar}=NO"
+					echo "${rcvar}=NO"
 				fi
 			fi
 			;;