devtools: speed up maintainers check

There is a huge speed improvement when forcing Unicode to be disabled
in this script.
In my test, it is improved from 13s to 6s.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>

devtools/check-maintainers.sh

@@ -34,6 +34,9 @@
 
 cd $(dirname $0)/..
 
+# speed up by ignoring Unicode details
+export LC_ALL=C
+
 # Get files matching paths with wildcards and / meaning recursing
 files () # <path> [<path> ...]
 {