[master] Fix a cut and paste error replacing concat with pick-first-value

RELNOTES

@@ -82,6 +82,11 @@ by Eric Young (eay@cryptsoft.com).
   reporting this issue and supplying its patch.
   [ISC-Bugs #42666]
 
+- Correct how the pick-first-value expression is written to a lease
+  file.  Previously it was written as a concat expression due to
+  a cut and paste error.
+  [ISC-Bugs #42253]
+
 			Changes since 4.3.4b1
 
 - None

common/tree.c

@@ -3645,7 +3645,7 @@ int write_expression (file, expr, col, indent, firstp)
 	      case expr_pick_first_value:
 		e = expr;
 		col = token_print_indent (file, col, indent, "", "",
-					  "concat");
+					  "pick-first-value");
 		col = token_print_indent (file, col, indent, " ", "",
 					  "(");
 		scol = col;