luarocks: Fix seeded uname (s/m) in siteconfig

LUAROCKS_UNAME_S/LUAROCKS_UNAME_M were being set automatically to host’s architecture and system/kernel name (e.g.. x86 and Darwin for the macOS)
The variables can now be supplied to configure via the supplied patch.
They are currently _S being hardcoded to “Linux” and _M set to the target architecture in the MakeFile.

Signed-off-by: David Thornley <david.thornley@touchstargroup.com>

lang/luarocks/Makefile

@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=luarocks
 PKG_VERSION:=2.2.2
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_PROTO:=git
@@ -43,6 +43,10 @@ CONFIGURE_ARGS = \
     --sysconfdir=/etc \
     --with-lua=$(STAGING_DIR)/host
 
+CONFIGURE_VARS = \
+	LUAROCKS_UNAME_S="Linux" \
+	LUAROCKS_UNAME_M="$(ARCH)"
+
 define Build/Compile
 	$(call Build/Compile/Default,build)
 endef