btrfs: drop unnecessary ASSERT from btrfs_submit_direct()

When on SINGLE block group, btrfs_get_io_geometry() will return "the
size of the block group - the offset of the logical address within the
block group" as geom.len. Since we allow up to 8 GiB zone size on zoned
filesystem, we can have up to 8 GiB block group, so can have up to 8 GiB
geom.len as well. With this setup, we easily hit the "ASSERT(geom.len <=
INT_MAX);".

The ASSERT looks like to guard btrfs_bio_clone_partial() and bio_trim()
which both take "int" (now u64 due to the previous patch). So to be
precise the ASSERT should check if clone_len <= UINT_MAX. But actually,
clone_len is already capped by bio.bi_iter.bi_size which is unsigned
int. So the ASSERT is not necessary.

Drop the ASSERT and properly compare submit_len and geom.len in u64.
Then, let the implicit casting to convert it to u64.
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -8239,8 +8239,8 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
 	u64 start_sector;
 	int async_submit = 0;
 	u64 submit_len;
-	int clone_offset = 0;
-	int clone_len;
+	u64 clone_offset = 0;
+	u64 clone_len;
 	u64 logical;
 	int ret;
 	blk_status_t status;
@@ -8288,9 +8288,9 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
 			status = errno_to_blk_status(ret);
 			goto out_err_em;
 		}
-		ASSERT(geom.len <= INT_MAX);
 
-		clone_len = min_t(int, submit_len, geom.len);
+		clone_len = min(submit_len, geom.len);
+		ASSERT(clone_len <= UINT_MAX);
 
 		/*
 		 * This will never fail as it's passing GPF_NOFS and