wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index f0e3e9e..26c2de2 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -369,7 +369,7 @@
 	if (!res) {
 		struct inode *inode = d_inode(dentry);
 
-		mutex_lock(&inode->i_mutex);
+		inode_lock(inode);
 		if (finfo.i.dirEntNum == NCP_FINFO(inode)->dirEntNum) {
 			ncp_new_dentry(dentry);
 			val=1;
@@ -377,7 +377,7 @@
 			ncp_dbg(2, "found, but dirEntNum changed\n");
 
 		ncp_update_inode2(inode, &finfo);
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 	}
 
 finished:
@@ -639,9 +639,9 @@
 	} else {
 		struct inode *inode = d_inode(newdent);
 
-		mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
+		inode_lock_nested(inode, I_MUTEX_CHILD);
 		ncp_update_inode2(inode, entry);
-		mutex_unlock(&inode->i_mutex);
+		inode_unlock(inode);
 	}
 
 	if (ctl.idx >= NCP_DIRCACHE_SIZE) {