pstore: Replace classic kmalloc code pattern with typed argument

Using a short Coccinelle script, it is possible to replace the classic
kmalloc code patterns with the typed information:

@alloc@
type TYPE;
TYPE *P;
expression GFP;
identifier ALLOC =~ "k[mz]alloc";
@@

	P = ALLOC(
-		\(sizeof(*P)\|sizeof(TYPE)\), GFP)
+		P, GFP)

Show this just for kmalloc/kzalloc usage in fs/pstore as an example.

Doing this for all allocator calls in the kernel touches much more:

 11941 files changed, 22459 insertions(+), 22345 deletions(-)

And obviously requires some more wrappers for kv*alloc, devm_*alloc,
etc.

Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com>
Cc: linux-hardening@vger.kernel.org