[S390] ftrace: drop nmi protection
[S390] ftrace: drop nmi protection

The function graph tracer used to have a protection against NMI
while entering a function entry tracing. But this is useless now,
the tracer is reentrant and the ring buffer supports NMI tracing.

Same as 07868b086cca784f4b532fc2ab574ec3a73b468a for x86.

Signed-off-by: Heiko Carstens <8dcf0f69152f32f23184f83357a3731522e56b9c@de.ibm.com>
Signed-off-by: Martin Schwidefsky <52616596d8f5df0d597e85ab515377f92f939c68@de.ibm.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs