getfacl and setfacl: Align with Linux

Make getfacl print two colons instead of one after "other" and "mask".
Change the help text for setfacl to indicate that there can be either
one colon or two.

winsup/utils/getfacl.c

@@ -98,14 +98,14 @@ usage (FILE * stream)
 	"     user:name or uid:perm\n"
 	"     group::perm\n"
 	"     group:name or gid:perm\n"
-	"     mask:perm\n"
-	"     other:perm\n"
+	"     mask::perm\n"
+	"     other::perm\n"
 	"     default:user::perm\n"
 	"     default:user:name or uid:perm\n"
 	"     default:group::perm\n"
 	"     default:group:name or gid:perm\n"
-	"     default:mask:perm\n"
-	"     default:other:perm\n"
+	"     default:mask::perm\n"
+	"     default:other::perm\n"
 	"\n");
     }
 }
@@ -265,10 +265,10 @@ main (int argc, char **argv)
 		n += printf ("group:%s:", groupname (acls[i].a_id));
 	      break;
 	    case CLASS_OBJ:
-	      printf ("mask:");
+	      printf ("mask::");
 	      break;
 	    case OTHER_OBJ:
-	      printf ("other:");
+	      printf ("other::");
 	      break;
 	    }
 	  n += printf ("%s", permstr (acls[i].a_perm));

winsup/utils/setfacl.c

@@ -119,7 +119,7 @@ getaclentry (action_t action, char *c, aclent_t *ace)
     }
   else if (!(ace->a_type & (USER_OBJ | GROUP_OBJ)))
     {
-      /* Mask and other entries may contain an extra colon. */
+      /* Mask and other entries may contain one or two colons. */
       if (*c == ':')
 	++c;
     }
@@ -558,8 +558,8 @@ usage (FILE *stream)
 "    u[ser]:uid:perm\n"
 "    g[roup]::perm\n"
 "    g[roup]:gid:perm\n"
-"    m[ask]:perm\n"
-"    o[ther]:perm\n"
+"    m[ask]:[:]perm\n"
+"    o[ther]:[:]perm\n"
 "\n"
 "  Default entries are like the above with the additional default identifier.\n"
 "  For example: \n"