scripts/spelling.txt: add "overlfow"

Add typo "overlfow" for "overflow". This typo was found and fixed in
net/sctp/tsnmap.c.

Link: https://lore.kernel.org/netdev/20210304055548.56829-1-drew@beagleboard.org/
Link: https://lkml.kernel.org/r/20210304072657.64577-1-drew@beagleboard.org
Signed-off-by: Drew Fustini <drew@beagleboard.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/spelling.txt b/scripts/spelling.txt
index 7beb426..8fe0283 100644
--- a/scripts/spelling.txt
+++ b/scripts/spelling.txt
@@ -1027,6 +1027,7 @@
 overaall||overall
 overhread||overhead
 overlaping||overlapping
+overlfow||overflow
 overide||override
 overrided||overridden
 overriden||overridden