Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/video/udlfb.c b/drivers/video/udlfb.c
index 2c8364e..68041d9 100644
--- a/drivers/video/udlfb.c
+++ b/drivers/video/udlfb.c
@@ -769,7 +769,7 @@
 
 		/*
 		 * If we have a damage-aware client, turn fb_defio "off"
-		 * To avoid perf imact of unecessary page fault handling.
+		 * To avoid perf imact of unnecessary page fault handling.
 		 * Done by resetting the delay for this fb_info to a very
 		 * long period. Pages will become writable and stay that way.
 		 * Reset to normal value when all clients have closed this fb.