Coccinelle: Move alloc directory into api directory

alloc contains various semantic patches related
to the allocation APIs
Signed-off-by: Nicolas Palix <npalix@diku.dk>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/coccinelle/alloc/kzalloc-simple.cocci → scripts/coccinelle/api/alloc/kzalloc-simple.cocci

 ///
-/// kzalloc should be used rather than kmalloc followed by memset 0
+/// Use kzalloc rather than kmalloc followed by memset with 0
+///
+/// This considers some simple cases that are common and easy to validate
+/// Note in particular that there are no ...s in the rule, so all of the
+/// matched code has to be contiguous
 ///
 // Confidence: High
 // Copyright: (C) 2009-2010 Julia Lawall, Nicolas Palix, DIKU.  GPLv2.