inode->i_op is never NULL

We used to have rather schizophrenic set of checks for NULL ->i_op even
though it had been eliminated years ago.  You'd need to go out of your
way to set it to NULL explicitly _and_ a bunch of code would die on
such inodes anyway.  After killing two remaining places that still
did that bogosity, all that crap can go away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/mm/memory.c b/mm/memory.c
index 0a2010a..7b9db65 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2266,7 +2266,7 @@
 		unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
 	}
 
-	if (inode->i_op && inode->i_op->truncate)
+	if (inode->i_op->truncate)
 		inode->i_op->truncate(inode);
 	return 0;
 
@@ -2286,7 +2286,7 @@
 	 * a way to truncate a range of blocks (punch a hole) -
 	 * we should return failure right now.
 	 */
-	if (!inode->i_op || !inode->i_op->truncate_range)
+	if (!inode->i_op->truncate_range)
 		return -ENOSYS;
 
 	mutex_lock(&inode->i_mutex);