exfat-nofuse: use $(KERNEL_MAKE) to account for reproducible build

This leverages on -iremap flag embedded there since the build system
commit 4ed356fa719e ("kernel.mk: add KCFLAGS to make kmods reproducible")

Reported-by: Paul Spooren <mail@aparcar.org>
Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

kernel/exfat-nofuse/Makefile

@@ -10,7 +10,7 @@ include $(TOPDIR)/rules.mk
 include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=exfat-nofuse
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE_URL:=https://github.com/dorimanx/exfat-nofuse.git
 PKG_SOURCE_PROTO:=git
@@ -36,15 +36,10 @@ define KernelPackage/fs-exfat0/description
 	Kernel module for ExFAT Filesytems
 endef
 
-MAKE_OPTS:= \
-	ARCH="$(LINUX_KARCH)" \
-	CROSS_COMPILE="$(TARGET_CROSS)" \
-	M="$(PKG_BUILD_DIR)"
-
 define Build/Compile
-	$(MAKE) -C "$(LINUX_DIR)" \
-		$(MAKE_OPTS) \
+	$(KERNEL_MAKE) \
 		CONFIG_EXFAT_FS=m \
+		M="$(PKG_BUILD_DIR)" \
 		modules
 endef