Send some error output to gdb_stderr

This changes some code to send some error messages to gdb_stderr
rather than gdb_stdout.

gdb/breakpoint.c

@@ -13063,9 +13063,10 @@ update_breakpoint_locations (struct breakpoint *b,
       /* Ranged breakpoints have only one start location and one end
 	 location.  */
       b->enable_state = bp_disabled;
-      printf_unfiltered (_("Could not reset ranged breakpoint %d: "
-			   "multiple locations found\n"),
-			 b->number);
+      fprintf_unfiltered (gdb_stderr,
+			  _("Could not reset ranged breakpoint %d: "
+			    "multiple locations found\n"),
+			  b->number);
       return;
     }