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>

fs/proc/proc_sysctl.c

@@ -31,7 +31,6 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
 	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
 	inode->i_flags |= S_PRIVATE; /* tell selinux to ignore this inode */
 	inode->i_mode = table->mode;
-	inode->i_uid = inode->i_gid = 0;
 	if (!table->child) {
 		inode->i_mode |= S_IFREG;
 		inode->i_op = &proc_sys_inode_operations;