treewide: update cifs-utils attr references (cifs_utils -> cifs-utils)

nixos/modules/tasks/filesystems/cifs.nix

···
 {
   config = {
 
-    system.fsPackages = mkIf (any (fs: fs == "cifs") config.boot.supportedFilesystems) [ pkgs.cifs_utils ];
+    system.fsPackages = mkIf (any (fs: fs == "cifs") config.boot.supportedFilesystems) [ pkgs.cifs-utils ];
 
     boot.initrd.availableKernelModules = mkIf inInitrd
       [ "cifs" "nls_utf8" "hmac" "md4" "ecb" "des_generic" "sha256" ];
 
     boot.initrd.extraUtilsCommands = mkIf inInitrd
       ''
-        copy_bin_and_libs ${pkgs.cifs_utils}/sbin/mount.cifs
+        copy_bin_and_libs ${pkgs.cifs-utils}/sbin/mount.cifs
       '';
 
   };