Make open_exec() and sys_uselib() use may_open(), instead of duplicating its parts

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/exec.c b/fs/exec.c
index 639177b..41ae8e0 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -126,11 +126,7 @@
 	if (nd.path.mnt->mnt_flags & MNT_NOEXEC)
 		goto exit;
 
-	error = inode_permission(nd.path.dentry->d_inode,
-				 MAY_READ | MAY_EXEC | MAY_OPEN);
-	if (error)
-		goto exit;
-	error = ima_path_check(&nd.path, MAY_READ | MAY_EXEC | MAY_OPEN);
+	error = may_open(&nd.path, MAY_READ | MAY_EXEC | MAY_OPEN, 0);
 	if (error)
 		goto exit;
 
@@ -677,10 +673,7 @@
 	if (nd.path.mnt->mnt_flags & MNT_NOEXEC)
 		goto out_path_put;
 
-	err = inode_permission(nd.path.dentry->d_inode, MAY_EXEC | MAY_OPEN);
-	if (err)
-		goto out_path_put;
-	err = ima_path_check(&nd.path, MAY_EXEC | MAY_OPEN);
+	err = may_open(&nd.path, MAY_EXEC | MAY_OPEN, 0);
 	if (err)
 		goto out_path_put;