kconfig: remove redundant NULL pointer check before free()

Passing NULL to free() is allowed and is a no-op.

Remove redundant NULL pointer checks.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/kconfig/confdata.c

@@ -432,8 +432,7 @@ int conf_read_simple(const char *name, int def)
 		case S_INT:
 		case S_HEX:
 		case S_STRING:
-			if (sym->def[def].val)
-				free(sym->def[def].val);
+			free(sym->def[def].val);
 			/* fall through */
 		default:
 			sym->def[def].val = NULL;

scripts/kconfig/util.c

@@ -42,8 +42,7 @@ struct gstr str_new(void)
 /* Free storage for growable string */
 void str_free(struct gstr *gs)
 {
-	if (gs->s)
-		free(gs->s);
+	free(gs->s);
 	gs->s = NULL;
 	gs->len = 0;
 }