block: constify struct blk_integrity_profile

blk_integrity_profile's are never modified, so mark them 'const' so that
they are placed in .rodata and benefit from memory protection.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 9f0ff5b..b3622cb 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -389,7 +389,7 @@ static int blk_integrity_nop_fn(struct blk_integrity_iter *iter)
 	return 0;
 }
 
-static struct blk_integrity_profile nop_profile = {
+static const struct blk_integrity_profile nop_profile = {
 	.name = "nop",
 	.generate_fn = blk_integrity_nop_fn,
 	.verify_fn = blk_integrity_nop_fn,