Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index 76b0598..962cdb2 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -905,7 +905,7 @@
  *
  * returns 1 if
  *  - we are inside irq code
- *  - we just extered irq code
+ *  - we just entered irq code
  *
  * retunns 0 if
  *  - funcgraph-interrupts option is set