criu/pie: kill util-fd.c

The functions it provides, send_fds() and receive_fds(), are already
provided by compel/plugins/std.built-in.o (compel/plugins/std/fds.c)
which is linked into both parasite and restorer.

This fixes the following issue (for some reason, reported on ARMv7,
see https://travis-ci.org/kolyshkin/criu/jobs/195367825):

  LINK     criu/pie/parasite.built-in.o
  GEN      criu/pie/parasite.built-in.bin.o
criu/pie/pie.lib.a(util-fd.o): In function `send_fds':
/criu/include/common/scm-code.c:56: multiple definition of `send_fds'
criu/pie/parasite.built-in.o:/criu/include/common/scm-code.c:56: first
defined here
criu/pie/pie.lib.a(util-fd.o): In function `recv_fds':
/criu/include/common/scm-code.c:79: multiple definition of `recv_fds'
criu/pie/parasite.built-in.o:/criu/include/common/scm-code.c:79: first
defined here
criu/pie/Makefile:53: recipe for target
'criu/pie/parasite.built-in.bin.o' failed
make[2]: *** [criu/pie/parasite.built-in.bin.o] Error 1

travis-ci: success for criu/pie: kill util-fd.c
Signed-off-by: Kir Kolyshkin <[email protected]>
Signed-off-by: Pavel Emelyanov <[email protected]>

Author: kolyshkin

criu/pie/Makefile.library

@@ -3,7 +3,7 @@ lib-name		:= pie.lib.a
 CFLAGS			+= -fno-stack-protector -DCR_NOGLIBC -fpie
 LDFLAGS			+= -z noexecstack
 
-lib-y			+= util-fd.o util.o
+lib-y			+= util.o
 
 ifeq ($(VDSO),y)
         lib-y		+= util-vdso.o parasite-vdso.o ./$(ARCH_DIR)/vdso-pie.o