Untangling ima mess, part 2: deal with counters

* do ima_get_count() in __dentry_open()
* stop doing that in followups
* move ima_path_check() to right after nameidata_to_filp()
* don't bump counters on it

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

fs/open.c

@@ -30,6 +30,7 @@
 #include <linux/audit.h>
 #include <linux/falloc.h>
 #include <linux/fs_struct.h>
+#include <linux/ima.h>
 
 #include "internal.h"
 
@@ -857,6 +858,7 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
 		if (error)
 			goto cleanup_all;
 	}
+	ima_counts_get(f);
 
 	f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);