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>

net/sunrpc/rpc_pipe.c

@@ -522,8 +522,6 @@ rpc_get_inode(struct super_block *sb, int mode)
 	if (!inode)
 		return NULL;
 	inode->i_mode = mode;
-	inode->i_uid = inode->i_gid = 0;
-	inode->i_blocks = 0;
 	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 	switch(mode & S_IFMT) {
 		case S_IFDIR: