selftests/powerpc: Don't use setaffinity in tm-tmspr

This test tries to set affinity to CPUs that don't exist, especially
if the set of online CPUs doesn't start at 0.

But there's no real reason for it to use setaffinity in the first
place, it's just trying to create lots of threads to cause contention.
So drop the setaffinity entirely.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200813013445.686464-2-mpe@ellerman.id.au

tools/testing/selftests/powerpc/tm/tm-tmspr.c

@@ -38,14 +38,8 @@ int	passed = 1;
 
 void tfiar_tfhar(void *in)
 {
-	int i, cpu;
 	unsigned long tfhar, tfhar_rd, tfiar, tfiar_rd;
-	cpu_set_t cpuset;
-
-	CPU_ZERO(&cpuset);
-	cpu = (unsigned long)in >> 1;
-	CPU_SET(cpu, &cpuset);
-	sched_setaffinity(0, sizeof(cpuset), &cpuset);
+	int i;
 
 	/* TFIAR: Last bit has to be high so userspace can read register */
 	tfiar = ((unsigned long)in) + 1;