Fix for plotyy demo

[Michael Goffioul]

Index: scripts/plot/plotyy.m
===================================================================
RCS file: /cvs/octave/scripts/plot/plotyy.m,v
retrieving revision 1.9
diff -c -p -r1.9 plotyy.m
*** scripts/plot/plotyy.m       4 Dec 2007 03:03:55 -0000       1.9
--- scripts/plot/plotyy.m       13 Dec 2007 09:03:03 -0000
*************** endfunction
*** 131,137 ****
  %! x = 0:0.1:2*pi;
  %! y1 = sin (x);
  %! y2 = exp (x - 1);
! %! ax = plotyy (x, y1, x - 1, y2, @@plot, @@semilogy);
  %! xlabel ("X");
  %! ylabel (ax(1), "Axis 1");
  %! ylabel (ax(2), "Axis 2");
--- 131,137 ----
  %! x = 0:0.1:2*pi;
  %! y1 = sin (x);
  %! y2 = exp (x - 1);
! %! ax = plotyy (x, y1, x - 1, y2, @plot, @semilogy);
  %! xlabel ("X");
  %! ylabel (ax(1), "Axis 1");
  %! ylabel (ax(2), "Axis 2");