alpha: Don't force -Werror.

There are outstanding gcc 4.6 warnings that need to be cleaned up
in the subdirectory.  No sense forcing the issue immediately.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/alpha/kernel/Makefile

@@ -4,7 +4,7 @@
 
 extra-y		:= head.o vmlinux.lds
 asflags-y	:= $(KBUILD_CFLAGS)
-ccflags-y	:= -Werror -Wno-sign-compare
+ccflags-y	:= -Wno-sign-compare
 
 obj-y    := entry.o traps.o process.o init_task.o osf_sys.o irq.o \
 	    irq_alpha.o signal.o setup.o ptrace.o time.o \