make doc example work on python 2.4

doc/tutorial/using_gpu.txt

@@ -47,7 +47,10 @@ file and run it.
     t1 = time.time()
     print 'Looping %d times took' % iters, t1 - t0, 'seconds'
     print 'Result is', r
-    print 'Used the', 'cpu' if numpy.any([isinstance(x.op, T.Elemwise) for x in f.maker.fgraph.toposort()]) else 'gpu'
+    if numpy.any([isinstance(x.op, T.Elemwise) for x in f.maker.fgraph.toposort()]):
+        print 'Used the cpu'
+    else:
+        print 'Used the gpu'
 
 The program just computes the exp() of a bunch of random numbers.
 Note that we use the `shared` function to
@@ -105,7 +108,10 @@ after the T.exp(x) is replaced by a GPU version of exp().
     print 'Looping %d times took' % iters, t1 - t0, 'seconds'
     print 'Result is', r
     print 'Numpy result is', numpy.asarray(r)
-    print 'Used the', 'cpu' if numpy.any([isinstance(x.op, T.Elemwise) for x in f.maker.fgraph.toposort()]) else 'gpu'
+    if numpy.any([isinstance(x.op, T.Elemwise) for x in f.maker.fgraph.toposort()]):
+        print 'Used the cpu'
+    else:
+        print 'Used the gpu'
 
 The output from this program is
 
@@ -161,7 +167,10 @@ that it has the un-wanted side-effect of really slowing things down.
     print 'Looping %d times took' % iters, t1 - t0, 'seconds'
     print 'Result is', r
     print 'Numpy result is', numpy.asarray(r)
-    print 'Used the', 'cpu' if numpy.any([isinstance(x.op,T.Elemwise) for x in f.maker.fgraph.toposort()]) else 'gpu'
+    if numpy.any([isinstance(x.op, T.Elemwise) for x in f.maker.fgraph.toposort()]):
+        print 'Used the cpu'
+    else:
+        print 'Used the gpu'
 
 Running this version of the code takes just under 0.05 seconds, over 140x faster than
 the CPU implementation!