Turn on CONFIG_FUNCTION_TRACER option will encounter a linking error

[AceLan Kao]

I turn on the following options and encountered a linking error
CONFIG_FUNCTION_TRACER=y
CONFIG_FUNCTION_PROFILER=y
CONFIG_FTRACE_SELFTEST=y
CONFIG_FTRACE_STARTUP_TEST=y

The erroe message is as below
init/built-in.o: In function `do_one_initcall':
calibrate.c:(.text+0x14): undefined reference to `__gnu_mcount_nc'
init/built-in.o: In function `run_init_process':
calibrate.c:(.text+0x1e0): undefined reference to `__gnu_mcount_nc'
init/built-in.o: In function `init_post':
calibrate.c:(.text+0x20c): undefined reference to `__gnu_mcount_nc'
init/built-in.o: In function `name_to_dev_t':
calibrate.c:(.text+0x330): undefined reference to `__gnu_mcount_nc'
init/built-in.o: In function `rest_init':
calibrate.c:(.ref.text+0x10): undefined reference to `__gnu_mcount_nc'
init/built-in.o:calibrate.c:(.cpuinit.text+0x10): more undefined references to `__gnu_mcount_nc' follow
make[3]: *** [.tmp_vmlinux1] Error 1
make[2]: *** [sub-make] Error 2

[AceLan Kao (acelankao)]

The __gnu_mcount_nc is implemented in this comment, just cherry-pick this commit will fix the problem
a8a48cd5add67494d96c13718cab36c465863d07