perf build failed on linux -next on i386 build build error: perf-in.o: In function `libunwind__x86_reg_id': tools/perf/util/libunwind/../../arch/x86/util/unwind-libunwind.c:109: undefined reference to `pr_err' tools/perf/util/libunwind/../../arch/x86/util/unwind-libunwind.c:109: undefined reference to `pr_err' - Naresh
