stubdom: allow to build with older tool chain

GNU make prior to 3.81 doesn't support $(realpath ...). This fixes a
regression introduced in 23368:0f670f5146c8 (the option tested via
cc-option-add got interpreted as the argument of the -I compiler
option, as its intended argument was blank, and hence the compiler was
falsely considered to support *any* option in the pciutils sub-tree).

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>

diff --git a/Makefile b/Makefile
index 938fc0ac17ad514b808cd13bfe21fa2e009396e7..370505951612f4fe42da647f0fb6aa09477e5df7 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -158,7 +158,7 @@ $(LIBPCI_STAMPFILE): pciutils-$(XEN_TARGET_ARCH) $(NEWLIB_STAMPFILE) $(ZLIB_STAM
          chmod u+w lib/config.h && \
          echo '#define PCILIB_VERSION "$(LIBPCI_VERSION)"' >> lib/config.h && \
          ln -sf ../../libpci.config.mak lib/config.mk && \
-         $(CROSS_MAKE) CC="$(CC) $(TARGET_CPPFLAGS) $(TARGET_CFLAGS) -I$(realpath $(MINI_OS)/include)" lib/libpci.a && \
+         $(CROSS_MAKE) CC="$(CC) $(TARGET_CPPFLAGS) $(TARGET_CFLAGS) -I$(call realpath,$(MINI_OS)/include)" lib/libpci.a && \
          $(INSTALL_DATA) lib/libpci.a $(CROSS_PREFIX)/$(GNU_TARGET_ARCH)-xen-elf/lib/ && \
          $(INSTALL_DIR) $(CROSS_PREFIX)/$(GNU_TARGET_ARCH)-xen-elf/include/pci && \
          $(INSTALL_DATA) lib/config.h lib/header.h lib/pci.h lib/types.h $(CROSS_PREFIX)/$(GNU_TARGET_ARCH)-xen-elf/include/pci/ \