Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 67fea9d..0791b13 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1347,7 +1347,7 @@
 
 	/*
 	 * Now that all the timers on our list have the firing flag,
-	 * noone will touch their list entries but us.  We'll take
+	 * no one will touch their list entries but us.  We'll take
 	 * each timer's lock before clearing its firing flag, so no
 	 * timer call will interfere.
 	 */