input: vcd: try to continue when a vector was found

input: vcd: try to continue when a vector was found

No need to bail out on vectors. As long as there are tokens left, we can
try to parse the rest. Also, print a message so the user knows what's
going on. Here is a testcase vcd:

$timescale 1 ns $end
$var wire 1 n0 addr_0 $end
$var wire 1 n1 addr_1 $end
$enddefinitions $end
#0
0n0
b1 n1
#1
1n0
b0 n1
#2
0n0
b1 n1

Signed-off-by: Wolfram Sang <redacted>