KVM: selftests: Fix compiling errors when initializing the static structure

Errors like below were produced from test_util.c when compiling the KVM
selftests on my local platform.

lib/test_util.c: In function 'vm_mem_backing_src_alias':
lib/test_util.c:177:12: error: initializer element is not constant
.flag = anon_flags,
^~~~~~~~~~
lib/test_util.c:177:12: note: (near initialization for 'aliases[0].flag')

The reason is that we are using non-const expressions to initialize the
static structure, which will probably trigger a compiling error/warning
on stricter GCC versions. Fix it by converting the two const variables
"anon_flags" and "anon_huge_flags" into more stable macros.

Fixes: b3784bc28ccc0 ("KVM: selftests: refactor vm_mem_backing_src_type flags")
Reported-by: Zenghui Yu <[e-mail]>
Signed-off-by: Yanan Wang <[e-mail]>
Message-Id: <[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

tools/testing/selftests/kvm/lib/test_util.c

···
 	return 0;
 }
 
+#define ANON_FLAGS	(MAP_PRIVATE | MAP_ANONYMOUS)
+#define ANON_HUGE_FLAGS	(ANON_FLAGS | MAP_HUGETLB)
+
 const struct vm_mem_backing_src_alias *vm_mem_backing_src_alias(uint32_t i)
 {
-	static const int anon_flags = MAP_PRIVATE | MAP_ANONYMOUS;
-	static const int anon_huge_flags = anon_flags | MAP_HUGETLB;
-
 	static const struct vm_mem_backing_src_alias aliases[] = {
 		[VM_MEM_SRC_ANONYMOUS] = {
 			.name = "anonymous",
-			.flag = anon_flags,
+			.flag = ANON_FLAGS,
 		},
 		[VM_MEM_SRC_ANONYMOUS_THP] = {
 			.name = "anonymous_thp",
-			.flag = anon_flags,
+			.flag = ANON_FLAGS,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB] = {
 			.name = "anonymous_hugetlb",
-			.flag = anon_huge_flags,
+			.flag = ANON_HUGE_FLAGS,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_16KB] = {
 			.name = "anonymous_hugetlb_16kb",
-			.flag = anon_huge_flags | MAP_HUGE_16KB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_16KB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_64KB] = {
 			.name = "anonymous_hugetlb_64kb",
-			.flag = anon_huge_flags | MAP_HUGE_64KB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_64KB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_512KB] = {
 			.name = "anonymous_hugetlb_512kb",
-			.flag = anon_huge_flags | MAP_HUGE_512KB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_512KB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_1MB] = {
 			.name = "anonymous_hugetlb_1mb",
-			.flag = anon_huge_flags | MAP_HUGE_1MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_1MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_2MB] = {
 			.name = "anonymous_hugetlb_2mb",
-			.flag = anon_huge_flags | MAP_HUGE_2MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_2MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_8MB] = {
 			.name = "anonymous_hugetlb_8mb",
-			.flag = anon_huge_flags | MAP_HUGE_8MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_8MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_16MB] = {
 			.name = "anonymous_hugetlb_16mb",
-			.flag = anon_huge_flags | MAP_HUGE_16MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_16MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_32MB] = {
 			.name = "anonymous_hugetlb_32mb",
-			.flag = anon_huge_flags | MAP_HUGE_32MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_32MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_256MB] = {
 			.name = "anonymous_hugetlb_256mb",
-			.flag = anon_huge_flags | MAP_HUGE_256MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_256MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_512MB] = {
 			.name = "anonymous_hugetlb_512mb",
-			.flag = anon_huge_flags | MAP_HUGE_512MB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_512MB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_1GB] = {
 			.name = "anonymous_hugetlb_1gb",
-			.flag = anon_huge_flags | MAP_HUGE_1GB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_1GB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_2GB] = {
 			.name = "anonymous_hugetlb_2gb",
-			.flag = anon_huge_flags | MAP_HUGE_2GB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_2GB,
 		},
 		[VM_MEM_SRC_ANONYMOUS_HUGETLB_16GB] = {
 			.name = "anonymous_hugetlb_16gb",
-			.flag = anon_huge_flags | MAP_HUGE_16GB,
+			.flag = ANON_HUGE_FLAGS | MAP_HUGE_16GB,
 		},
 		[VM_MEM_SRC_SHMEM] = {
 			.name = "shmem",