Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/net/igb/e1000_phy.c b/drivers/net/igb/e1000_phy.c
index 6694bf3..d639706 100644
--- a/drivers/net/igb/e1000_phy.c
+++ b/drivers/net/igb/e1000_phy.c
@@ -1421,7 +1421,7 @@
 }
 
 /**
- *  igb_check_downshift - Checks whether a downshift in speed occured
+ *  igb_check_downshift - Checks whether a downshift in speed occurred
  *  @hw: pointer to the HW structure
  *
  *  Success returns 0, Failure returns 1