parisc: Eliminate memset after alloc_bootmem_pages

alloc_bootmem and related function always return zeroed region of
memory. Thus a memset after calls to these functions is unnecessary.

The following Coccinelle semantic patch was used for making the change:

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\)(...)
... when != E
- memset(E,0,E1);

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/mm/init.c

@@ -728,7 +728,6 @@ static void __init pagetable_init(void)
 #endif
 
 	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);
-	memset(empty_zero_page, 0, PAGE_SIZE);
 }
 
 static void __init gateway_init(void)