Add vzalloc() and vmalloc() functions to alloc-with-multiplies check in checkpatch.pl

[GustavoARSilva]

Update checkpatch.pl to check for instances of vzalloc()/vmalloc() that could be replaced with their 2-factor multiplication argument form vcalloc()/vmalloc_array (). So, they can be caught before new code is even committed.

Related to:
#187

[kees]

Did this get sent upstream? I see the earlier commit 73f1d07, though?