ppc64: convert xmon to use kallsyms now its compiled in by default.

arch/ppc64/Makefile

@@ -18,7 +18,7 @@ KERNELLOAD	:= 0xc000000000000000
 LDFLAGS		:= -m elf64ppc
 LDFLAGS_vmlinux	:= -Bstatic -e $(KERNELLOAD) -Ttext $(KERNELLOAD)
 CFLAGS		+= -msoft-float -pipe -Wno-uninitialized -mminimal-toc \
-		-mtraceback=full -mcpu=power4
+		-mcpu=power4
 
 have_zero_bss := $(shell if $(CC) -fno-zero-initialized-in-bss -S -o /dev/null -xc /dev/null > /dev/null 2>&1; then echo y; else echo n; fi)