arm64: kasan: Use actual memory node when populating the kernel image shadow

With the 16KB or 64KB page configurations, the generic
vmemmap_populate() implementation warns on potential offnode
page_structs via vmemmap_verify() because the arm64 kasan_init() passes
NUMA_NO_NODE instead of the actual node for the kernel image memory.

Fixes: f9040773 ("arm64: move kernel image to base of vmalloc area")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: James Morse <james.morse@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>

arch/arm64/mm/kasan_init.c

@@ -152,7 +152,8 @@ void __init kasan_init(void)
 
 	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
 
-	vmemmap_populate(kimg_shadow_start, kimg_shadow_end, NUMA_NO_NODE);
+	vmemmap_populate(kimg_shadow_start, kimg_shadow_end,
+			 pfn_to_nid(virt_to_pfn(_text)));
 
 	/*
 	 * vmemmap_populate() has populated the shadow region that covers the