Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 145b3d0d..4c36ef6 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -234,7 +234,7 @@
 		 * the data. For our userspace tools it is important
 		 * to dump areas with ecc errors !
 		 * For kernel internal usage it also might return -EUCLEAN
-		 * to signal the caller that a bitflip has occured and has
+		 * to signal the caller that a bitflip has occurred and has
 		 * been corrected by the ECC algorithm.
 		 * Userspace software which accesses NAND this way
 		 * must be aware of the fact that it deals with NAND