maint: use EXIT_SUCCESS and EXIT_FAILURE, not 0 and 1 in "usage", too

Convert by running these commands:
perl -pi -e 's/\b(usage ?)\(1\)/$1(EXIT_FAILURE)/' \
  fish/fish.c fuse/guestmount.c
perl -pi -e 's/\b(usage ?)\(0\)/$1(EXIT_SUCCESS)/' \
  fish/fish.c fuse/guestmount.c
* fish/fish.c (main): Replace 0/1 with EXIT_SUCCESS/EXIT_FAILURE.
* fuse/guestmount.c (main): Likewise.

1 files changed, 2 insertions, 2 deletions

diff --git a/fish/fish.c b/fish/fish.c
index 4f515033..7dae815d 100644
--- a/fish/fish.c
+++ b/fish/fish.c
@@ -322,10 +322,10 @@ main (int argc, char *argv[])
       break;
 
     case HELP_OPTION:
-      usage (0);
+      usage (EXIT_SUCCESS);
 
     default:
-      usage (1);
+      usage (EXIT_FAILURE);
     }
   }