confgen: Fix bug with JSON metadata conditional range generation

When generating JSON metadata for ranges where there are conditional ranges (ie different allowed range
depending on another config setting), the JSON metadata would always have the last named range as
the expression was not evaluated properly.

Thanks to ulfalizer on GitHub for pointing this out.

Closes https://github.com/espressif/esp-idf/issues/2195

tools/kconfig_new/confgen.py

@@ -221,9 +221,9 @@ def write_json_menus(config, filename):
                 greatest_range = None
                 if len(sym.ranges) > 0:
                     # Note: Evaluating the condition using kconfiglib's expr_value
-                    # should have one result different from value 0 ("n").
+                    # should have one condition which is true
                     for min_range, max_range, cond_expr in sym.ranges:
-                        if kconfiglib.expr_value(cond_expr) != "n":
+                        if kconfiglib.expr_value(cond_expr):
                             greatest_range = [min_range, max_range]
                 new_json["range"] = greatest_range
 
@@ -232,9 +232,9 @@ def write_json_menus(config, filename):
             greatest_range = None
             if len(sym.ranges) > 0:
                 # Note: Evaluating the condition using kconfiglib's expr_value
-                # should have one result different from value 0 ("n").
+                # should have one condition which is true
                 for min_range, max_range, cond_expr in sym.ranges:
-                    if kconfiglib.expr_value(cond_expr) != "n":
+                    if kconfiglib.expr_value(cond_expr):
                         greatest_range = [int(min_range.str_value), int(max_range.str_value)]
 
             new_json = {