dax: Get rid of fs_dax_get_by_host() helper

Looks like nobody is using fs_dax_get_by_host() except fs_dax_get_by_bdev()
and it can easily use dax_get_by_host() instead.

IIUC, fs_dax_get_by_host() was only introduced so that one could compile
with CONFIG_FS_DAX=n and CONFIG_DAX=m. fs_dax_get_by_bdev() achieves
the same purpose and hence it looks like fs_dax_get_by_host() is not
needed anymore.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200106181117.GA16248@redhat.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dax/super.c

@@ -61,7 +61,7 @@ struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
 {
 	if (!blk_queue_dax(bdev->bd_queue))
 		return NULL;
-	return fs_dax_get_by_host(bdev->bd_disk->disk_name);
+	return dax_get_by_host(bdev->bd_disk->disk_name);
 }
 EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev);
 #endif

include/linux/dax.h

@@ -129,11 +129,6 @@ static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
 			sectors);
 }
 
-static inline struct dax_device *fs_dax_get_by_host(const char *host)
-{
-	return dax_get_by_host(host);
-}
-
 static inline void fs_put_dax(struct dax_device *dax_dev)
 {
 	put_dax(dax_dev);
@@ -160,11 +155,6 @@ static inline bool generic_fsdax_supported(struct dax_device *dax_dev,
 	return false;
 }
 
-static inline struct dax_device *fs_dax_get_by_host(const char *host)
-{
-	return NULL;
-}
-
 static inline void fs_put_dax(struct dax_device *dax_dev)
 {
 }