efi_loader: do not use symbolic links

Symbolic links are not supported on all file systems, e.g. not on FAT. So
it is not wise to use them in our source tree.

Use a qualified path to refer to lib/efi_loader/efi_freestanding.c in
scripts/Makefile.lib instead.
Reported-by: NAlexander Graf <agraf@suse.de>
Signed-off-by: NHeinrich Schuchardt <xypron.glpk@gmx.de>
[agraf: Fix build with O=]
Signed-off-by: NAlexander Graf <agraf@suse.de>

lib/efi_selftest/efi_freestanding.c

-../efi_loader/efi_freestanding.c
\ No newline at end of file

scripts/Makefile.lib

@@ -389,7 +389,7 @@ $(obj)/efi_reloc.o: $(srctree)/arch/$(ARCH)/lib/$(EFI_RELOC:.o=.c) $(recordmcoun
 	$(call cmd,force_checksrc)
 	$(call if_changed_rule,cc_o_c)
 
-$(obj)/%_efi.so: $(obj)/%.o $(obj)/efi_crt0.o $(obj)/efi_reloc.o $(obj)/efi_freestanding.o
+$(obj)/%_efi.so: $(obj)/%.o $(obj)/efi_crt0.o $(obj)/efi_reloc.o $(obj)/../efi_loader/efi_freestanding.o
 	$(call cmd,efi_ld)
 
 # ACPI