mm: use octal not symbolic permissions

mm/*.c files use symbolic and octal styles for permissions.

Using octal and not symbolic permissions is preferred by many as more
readable.

https://lkml.org/lkml/2016/8/2/1945

Prefer the direct use of octal for permissions.

Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.

Before:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86

Miscellanea:

o Whitespace neatening around these conversions.

Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/frontswap.c

@@ -486,12 +486,11 @@ static int __init init_frontswap(void)
 	struct dentry *root = debugfs_create_dir("frontswap", NULL);
 	if (root == NULL)
 		return -ENXIO;
-	debugfs_create_u64("loads", S_IRUGO, root, &frontswap_loads);
-	debugfs_create_u64("succ_stores", S_IRUGO, root, &frontswap_succ_stores);
-	debugfs_create_u64("failed_stores", S_IRUGO, root,
-				&frontswap_failed_stores);
-	debugfs_create_u64("invalidates", S_IRUGO,
-				root, &frontswap_invalidates);
+	debugfs_create_u64("loads", 0444, root, &frontswap_loads);
+	debugfs_create_u64("succ_stores", 0444, root, &frontswap_succ_stores);
+	debugfs_create_u64("failed_stores", 0444, root,
+			   &frontswap_failed_stores);
+	debugfs_create_u64("invalidates", 0444, root, &frontswap_invalidates);
 #endif
 	return 0;
 }