fs/ntfs3: Fix fall-through warnings for Clang

Fix the following fallthrough warnings:

fs/ntfs3/inode.c:1792:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/ntfs3/index.c:178:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

This helps with the ongoing efforts to globally enable
-Wimplicit-fallthrough for Clang.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/index.c

@@ -175,6 +175,7 @@ static inline NTFS_CMP_FUNC get_cmp_func(const struct INDEX_ROOT *root)
 		default:
 			break;
 		}
+		break;
 	default:
 		break;
 	}

fs/ntfs3/inode.c

@@ -1789,6 +1789,7 @@ int ntfs_unlink_inode(struct inode *dir, const struct dentry *dentry)
 	switch (err) {
 	case 0:
 		drop_nlink(inode);
+		break;
 	case -ENOTEMPTY:
 	case -ENOSPC:
 	case -EROFS: