[PATCH] Unify usage strings declaration

All usage strings are now declared as static const char [].

This is carried over from my old git-pb branch.

Signed-off-by: Petr Baudis <pasky@ucw.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>

ls-tree.c

@@ -208,7 +208,7 @@ static int list(char **path)
 	return err;
 }
 
-static const char *ls_tree_usage =
+static const char ls_tree_usage[] =
 	"git-ls-tree [-d] [-r] [-z] <tree-ish> [path...]";
 
 int main(int argc, char **argv)