x86, build: Disable -fPIE when compiling with CONFIG_CC_STACKPROTECTOR=y

The arch/x86/Makefile uses scripts/gcc-x86_$(BITS)-has-stack-protector.sh
to check if cc1 supports -fstack-protector.  When -fPIE is passed to cc1,
these scripts fail causing stack protection to be disabled even when it
is available.

This fix is similar to commit c47efe5548abbf53c2f66e06dcb46183b11d6b22

Reported-by: Kai Dietrich <mail@cleeus.de>
Signed-off-by: Magnus Granberg <zorry@gentoo.org>
LKML-Reference: <20100913101319.748A1148E216@opensource.dyc.edu>
Signed-off-by: Anthony G. Basile <basile@opensource.dyc.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/Makefile

@@ -74,7 +74,7 @@ endif
 
 ifdef CONFIG_CC_STACKPROTECTOR
 	cc_has_sp := $(srctree)/scripts/gcc-x86_$(BITS)-has-stack-protector.sh
-        ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC) $(biarch)),y)
+        ifeq ($(shell $(CONFIG_SHELL) $(cc_has_sp) $(CC) $(KBUILD_CPPFLAGS) $(biarch)),y)
                 stackp-y := -fstack-protector
                 KBUILD_CFLAGS += $(stackp-y)
         else