Fix ps bug, last field wasn't expanding to width.

(Still fixing the fallout from that "Don't truncate number fields" logic rewrite.)
diff --git a/toys/posix/ps.c b/toys/posix/ps.c
index 6a9676c..4c66bcd 100644
--- a/toys/posix/ps.c
+++ b/toys/posix/ps.c
@@ -593,7 +593,10 @@
     len = pad = abslen;
     pad *= sign;
     // If last field is left justified, no trailing spaces.
-    if (!field->next && sign<0) pad = 0;
+    if (!field->next && sign<0) {
+      pad = 0;
+      len = width;
+    }
 
     if (TT.tty) width -= draw_trim(out, pad, len);
     else width -= printf("%*.*s", pad, len, out);