IB/uverbs: Use anon_inodes instead of private infinibandeventfs

The anon_inodes interface has been split to allow creating a bare
(non-installed) file pointer and also extended to allow specifying
O_RDONLY in the flags.  This makes it a suitable replacement for the
private "infinibandeventfs" pseudo-filesystem used by uverbs, and this
replacement saves a small chunk of boilerplate code.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/Kconfig b/drivers/infiniband/Kconfig
index dd0db67..975adce 100644
--- a/drivers/infiniband/Kconfig
+++ b/drivers/infiniband/Kconfig
@@ -20,6 +20,7 @@
 
 config INFINIBAND_USER_ACCESS
 	tristate "InfiniBand userspace access (verbs and CM)"
+	select ANON_INODES
 	---help---
 	  Userspace InfiniBand access support.  This enables the
 	  kernel side of userspace verbs and the userspace