CodingStyle: add kmalloc_array() to memory allocators

Add the new kmalloc_array() to the list of general-purpose memory
allocators in chapter 14.
Signed-off-by: NXi Wang <xi.wang@gmail.com>
Acked-by: NJesper Juhl <jj@chaosbits.net>
Acked-by: NPekka Enberg <penberg@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Documentation/CodingStyle

@@ -671,8 +671,9 @@ ones already enabled by DEBUG.
 		Chapter 14: Allocating memory
 
 The kernel provides the following general purpose memory allocators:
-kmalloc(), kzalloc(), kcalloc(), vmalloc(), and vzalloc().  Please refer to
-the API documentation for further information about them.
+kmalloc(), kzalloc(), kmalloc_array(), kcalloc(), vmalloc(), and
+vzalloc().  Please refer to the API documentation for further information
+about them.
 
 The preferred form for passing a size of a struct is the following:
 
@@ -686,6 +687,17 @@ Casting the return value which is a void pointer is redundant. The conversion
 from void pointer to any other pointer type is guaranteed by the C programming
 language.
 
+The preferred form for allocating an array is the following:
+
+	p = kmalloc_array(n, sizeof(...), ...);
+
+The preferred form for allocating a zeroed array is the following:
+
+	p = kcalloc(n, sizeof(...), ...);
+
+Both forms check for overflow on the allocation size n * sizeof(...),
+and return NULL if that occurred.
+
 
 		Chapter 15: The inline disease