5704 libzfs can only handle 255 filedescriptors

@@ -622,17 +622,17 @@
         if ((hdl->libzfs_fd = open(ZFS_DEV, O_RDWR)) < 0) {
                 free(hdl);
                 return (NULL);
         }
 
-        if ((hdl->libzfs_mnttab = fopen(MNTTAB, "r")) == NULL) {
+        if ((hdl->libzfs_mnttab = fopen(MNTTAB, "rF")) == NULL) {
                 (void) close(hdl->libzfs_fd);
                 free(hdl);
                 return (NULL);
         }
 
-        hdl->libzfs_sharetab = fopen("/etc/dfs/sharetab", "r");
+        hdl->libzfs_sharetab = fopen("/etc/dfs/sharetab", "rF");
 
         if (libzfs_core_init() != 0) {
                 (void) close(hdl->libzfs_fd);
                 (void) fclose(hdl->libzfs_mnttab);
                 (void) fclose(hdl->libzfs_sharetab);