[patch] dax: silence an uninitialized variable warning

[Dan Carpenter <dan.carpenter@oracle.com>]

I'm not positive, but it looks like it might be possible to reach the
end of this function and return an uninitialized value for "rc".  Anyway
it causes a static checker warning and let's silence it.

The warning was introduced in commit b2e0d1625e19 ('dax: fix lifetime of
in-kernel dax mappings with dax_map_atomic()').

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/fs/dax.c b/fs/dax.c
index 90322eb..3744e14 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -155,7 +155,8 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 	loff_t pos = start, max = start, bh_max = start;
 	bool hole = false, need_wmb = false;
 	struct block_device *bdev = NULL;
-	int rw = iov_iter_rw(iter), rc;
+	int rc = 0;
+	int rw = iov_iter_rw(iter);
 	long map_len = 0;
 	struct blk_dax_ctl dax = {
 		.addr = (void __pmem *) ERR_PTR(-EIO),