zero i_uid/i_gid on inode allocation

... and don't bother in callers.  Don't bother with zeroing i_blocks,
while we are at it - it's already been zeroed.

i_mode is not worth the effort; it has no common default value.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

drivers/infiniband/hw/ipath/ipath_fs.c

@@ -57,9 +57,6 @@ static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
 	}
 
 	inode->i_mode = mode;
-	inode->i_uid = 0;
-	inode->i_gid = 0;
-	inode->i_blocks = 0;
 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 	inode->i_private = data;
 	if ((mode & S_IFMT) == S_IFDIR) {