ANDROID: KVM: arm64: Fix missing_map type in hyp_alloc()

Should be size_t rather than int, to avoid overflow.

Bug: 431949163
Bug: 357781595
Reported-by: Hiroyuki Katsura <hk590@cam.ac.uk>
Change-Id: I33304da2559540d0e8915e4c12184a36fea8b18f
Signed-off-by: Keir Fraser <keirf@google.com>

arch/arm64/kvm/hyp/nvhe/alloc.c

@@ -549,7 +549,8 @@ void *hyp_alloc(size_t size)
 	struct hyp_allocator *allocator = &hyp_allocator;
 	struct chunk_hdr *chunk, *last_chunk;
 	unsigned long chunk_addr;
-	int missing_map, ret = 0;
+	size_t missing_map;
+	int ret = 0;
 
 	size = ALIGN(size ?: MIN_ALLOC, MIN_ALLOC);