LU-8117 build: fix lustre-ppc64 build on el7

Explicitly clear the LDFLAGS for kernel modules build so that
the vendor's overzealous linker flags don't create build failures.

Test-Parameters: trivial

Change-Id: I427cffb229a19a8ff0c2ba0c3ed2ac135f21e24d
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-on: http://review.whamcloud.com/20404


Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Minh Diep <minh.diep@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

autoMakefile.am

@@ -72,7 +72,7 @@ if LINUX
 all-am: modules
 
 modules: undef.h ldiskfs-sources
-	$(MAKE) CC="$(CC)" -C $(LINUX_OBJ) \
+	$(MAKE) LDFLAGS= CC="$(CC)" -C $(LINUX_OBJ) \
 	-f $(PWD)/build/Makefile LUSTRE_LINUX_CONFIG=$(LINUX_CONFIG) \
 	LINUXINCLUDE='-I$$(srctree)/arch/$$(SRCARCH)/include -Iarch/$$(SRCARCH)/include/generated -Iinclude $$(if $$(KBUILD_SRC),-Iinclude2 -I$$(srctree)/include) -I$$(srctree)/arch/$$(SRCARCH)/include/uapi -Iarch/$$(SRCARCH)/include/generated/uapi -I$$(srctree)/include/uapi -Iinclude/generated/uapi -include $(CONFIG_INCLUDE)' \
 	$(MODULE_TARGET)=$(PWD) -o tmp_include_depends -o scripts -o \

config/lustre-build-linux.m4

@@ -499,8 +499,8 @@ $2
 AC_DEFUN([LB_LINUX_COMPILE_IFELSE],
 [m4_ifvaln([$1], [AC_LANG_CONFTEST([AC_LANG_SOURCE([$1])])])dnl
 rm -f build/conftest.o build/conftest.mod.c build/conftest.ko
-SUBARCH=$(echo $target_cpu | sed -e 's/powerpc64le/powerpc/' -e 's/powerpc64/powerpc/' -e 's/x86_64/x86/' -e 's/i.86/x86/' -e 's/k1om/x86/' -e 's/aarch64/arm64/')
-AS_IF([AC_TRY_COMMAND(cp conftest.c build && make -d [$2] ${LD:+"LD=$LD"} CC="$CC" -f $PWD/build/Makefile LUSTRE_LINUX_CONFIG=$LINUX_CONFIG LINUXINCLUDE="$EXTRA_CHECK_INCLUDE -I$LINUX/arch/$SUBARCH/include -Iinclude -Iarch/$SUBARCH/include/generated -I$LINUX/include -Iinclude2 -I$LINUX/include/uapi -Iinclude/generated -I$LINUX/arch/$SUBARCH/include/uapi -Iarch/$SUBARCH/include/generated/uapi -I$LINUX/include/uapi -Iinclude/generated/uapi ${SPL_OBJ:+-include $SPL_OBJ/spl_config.h} ${ZFS_OBJ:+-include $ZFS_OBJ/zfs_config.h} ${SPL:+-I$SPL -I$SPL/include } ${ZFS:+-I$ZFS -I$ZFS/include} -include $CONFIG_INCLUDE" -o tmp_include_depends -o scripts -o include/config/MARKER -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $MODULE_TARGET=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
+SUBARCH=$(echo $target_cpu | sed -e 's/powerpc.*/powerpc/' -e 's/ppc.*/powerpc/' -e 's/x86_64/x86/' -e 's/i.86/x86/' -e 's/k1om/x86/' -e 's/aarch64.*/arm64/')
+AS_IF([AC_TRY_COMMAND(cp conftest.c build && make -d [$2] LDFLAGS= ${LD:+LD="$LD"} CC="$CC" -f $PWD/build/Makefile LUSTRE_LINUX_CONFIG=$LINUX_CONFIG LINUXINCLUDE="$EXTRA_CHECK_INCLUDE -I$LINUX/arch/$SUBARCH/include -Iinclude -Iarch/$SUBARCH/include/generated -I$LINUX/include -Iinclude2 -I$LINUX/include/uapi -Iinclude/generated -I$LINUX/arch/$SUBARCH/include/uapi -Iarch/$SUBARCH/include/generated/uapi -I$LINUX/include/uapi -Iinclude/generated/uapi ${SPL_OBJ:+-include $SPL_OBJ/spl_config.h} ${ZFS_OBJ:+-include $ZFS_OBJ/zfs_config.h} ${SPL:+-I$SPL -I$SPL/include } ${ZFS:+-I$ZFS -I$ZFS/include} -include $CONFIG_INCLUDE" -o tmp_include_depends -o scripts -o include/config/MARKER -C $LINUX_OBJ EXTRA_CFLAGS="-Werror-implicit-function-declaration $EXTRA_KCFLAGS" $MODULE_TARGET=$PWD/build) >/dev/null && AC_TRY_COMMAND([$3])],
 	[$4],
 	[_AC_MSG_LOG_CONFTEST
 m4_ifvaln([$5],[$5])dnl])