kbuild: update comment about KBUILD_ALLDIRS

Commit 000ec95fbe ("kbuild: pkg: rename scripts/package/Makefile to
scripts/Makefile.package") missed to update this comment.

Fixes: 000ec95fbe ("kbuild: pkg: rename scripts/package/Makefile to scripts/Makefile.package")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Makefile

@@ -1037,7 +1037,7 @@ export KBUILD_VMLINUX_OBJS := $(head-y) $(init-y) $(core-y) $(libs-y2) \
 export KBUILD_VMLINUX_LIBS := $(libs-y1)
 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
 export LDFLAGS_vmlinux
-# used by scripts/package/Makefile
+# used by scripts/Makefile.package
 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
 
 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)