get_maintainer: it's '--pattern-depth', not '-pattern-depth'

Though it appears that Perl's GetOptions will take either, the latter is
not documented in the options listing.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/get_maintainer.pl

@@ -813,7 +813,7 @@ Other options:
   --help => show this help information
 
 Default options:
-  [--email --nogit --git-fallback --m --n --l --multiline -pattern-depth=0
+  [--email --nogit --git-fallback --m --n --l --multiline --pattern-depth=0
    --remove-duplicates --rolestats]
 
 Notes: