build: replace `true` with a custom noop script

`true` might be a shell built-in, or simply not accessible in the hardcoded locations.
Replace it with a custom script that does nothing.

Signed-off-by: Ilya Katsnelson <me@0upti.me>

include/prereq-build.mk

@@ -238,4 +238,4 @@ prereq: $(STAGING_DIR_HOST)/bin/mkhash $(STAGING_DIR_HOST)/bin/xxd
 
 # Install ldconfig stub
 $(eval $(call TestHostCommand,ldconfig-stub,Failed to install stub, \
-	$(LN) $(firstword $(wildcard /bin/true /usr/bin/true)) $(STAGING_DIR_HOST)/bin/ldconfig))
+	$(LN) $(SCRIPT_DIR)/noop.sh $(STAGING_DIR_HOST)/bin/ldconfig))

scripts/noop.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+# This script does nothing, intentionally.