scripts/coccinelle: update for compatability with Coccinelle 0.2.4

For doubleinit.cocci, Coccinelle 0.2.4 requires a comma after ... in a
field list.  Coccinelle also now behaves gracefully when a definition is
provided for a virtual that doesn't exist, so there is no need for the
semantic patch code to check for this case.

Updated the documentation to reflect the fact that the best results will
now be obtained with Coccinelle version 0.2.4 or later.

Signed-off-by: Julia Lawall <julia@diku.dk>

Documentation/coccinelle.txt

@@ -36,6 +36,10 @@ as a regular user, and install it with
 
         sudo make install
 
+The semantic patches in the kernel will work best with Coccinelle version
+0.2.4 or later.  Using earlier versions may incur some parse errors in the
+semantic patch code, but any results that are obtained should still be
+correct.
 
  Using Coccinelle on the Linux kernel
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~