tracing/fastboot: fix initcalls disposition in bootgraph.pl

When bootgraph.pl parses a file, it gives one row
for each initcall's pid. But only few of them will
be displayed => the longest.

This patch corrects it by giving only a rows for pids
which have initcalls that will be displayed.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

scripts/bootgraph.pl

@@ -110,6 +110,12 @@ while (($key,$value) = each %start) {
 
 	if ($duration >= $threshold) {
 		my $s, $s2, $e, $y;
+		$pid = $pids{$key};
+
+		if (!defined($rows{$pid})) {
+			$rows{$pid} = $rowscount;
+			$rowscount = $rowscount + 1;
+		}
 		$s = ($value - $firsttime) * $mult;
 		$s2 = $s + 6;
 		$e = ($end{$key} - $firsttime) * $mult;