[PATCH] kbuild: use POSIX-compatible grep option

[Stefan Hansson <newbie13xd@gmail.com>]

--file is a GNU extension to grep which is not available in all
implementations (such as BusyBox). Use the -f option instead which is
eqvuialent according to the GNU grep manpage[1] and is present in
POSIX[2].

 [1] https://www.gnu.org/software/grep/manual/grep.html
 [2] https://pubs.opengroup.org/onlinepubs/9699919799/

Signed-off-by: Stefan Hansson <newbie13xd@gmail.com>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index c690361b393f..3513a6db66a2 100644
--- a/Makefile
+++ b/Makefile
@@ -1218,7 +1218,7 @@ quiet_cmd_ar_vmlinux.a = AR      $@
       cmd_ar_vmlinux.a = \
 	rm -f $@; \
 	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
-	$(AR) mPiT $$($(AR) t $@ | head -n1) $@ $$($(AR) t $@ | grep -F --file=$(srctree)/scripts/head-object-list.txt)
+	$(AR) mPiT $$($(AR) t $@ | head -n1) $@ $$($(AR) t $@ | grep -Ff $(srctree)/scripts/head-object-list.txt)
 
 targets += vmlinux.a
 vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
-- 
2.37.3