Revert "uml: fix gcc problem"

This reverts commit 22eecde2.  Uli
reports that it breaks UML on x86-64 with the Fedora 8 gcc (gcc 4.1.2),
causing a crash on startup. See

	http://marc.info/?l=linux-kernel&m=121011722806093&w=2

for a trace.
Reported-by: Ulrich Drepper <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/um/Makefile

@@ -77,10 +77,7 @@ include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
 KERNEL_DEFINES = $(strip -Derrno=kernel_errno -Dsigprocmask=kernel_sigprocmask \
 			 -Dmktime=kernel_mktime $(ARCH_KERNEL_DEFINES))
 KBUILD_CFLAGS += $(KERNEL_DEFINES)
-# Disable unit-at-a-time mode on pre-gcc-4.0 compilers, it makes gcc use
-# a lot more stack due to the lack of sharing of stacklots:
-KBUILD_CFLAGS += $(shell if [ $(call cc-version) -lt 0400 ] ; then \
-			echo $(call cc-option,-fno-unit-at-a-time); fi ;)
+KBUILD_CFLAGS += $(call cc-option,-fno-unit-at-a-time,)
 
 PHONY += linux