staging: lustre: llite: Use kzalloc and rewrite null tests

This patch removes some kzalloc-related macros and rewrites the
associated null tests to use !x rather than x == NULL.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/

)

// <smpl>
@@
expression ptr;
statement S,S1;
@@

  \(OBD_ALLOC\|OBD_ALLOC_WAIT\|OBD_ALLOC_PTR\|OBD_ALLOC_PTR_WAIT\)(ptr,...);
  if (
+     !
      ptr
-      == NULL
     ) S else S1

@@
expression ptr,size;
@@

- OBD_ALLOC(ptr,size)
+ ptr = kzalloc(size, GFP_NOFS)

@@
expression ptr,size;
@@

- OBD_ALLOC_WAIT(ptr,size)
+ ptr = kzalloc(size, GFP_KERNEL)

@@
expression ptr,size;
@@

- OBD_ALLOC_PTR(ptr)
+ ptr = kzalloc(sizeof(*ptr), GFP_NOFS)

@@
expression ptr,size;
@@

- OBD_ALLOC_PTR_WAIT(ptr,size)
+ ptr = kzalloc(sizeof(*ptr), GFP_KERNEL)
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>