powerpc/perf: Change the data type for the variable 'ncpu' in IMC code

Change the data type for the variable 'ncpu' in ppc_core_imc_cpu_offline(),
since cpumask_any_but() returns an 'int' value.
Signed-off-by: NAnju T Sudhakar <anju@linux.vnet.ibm.com>
Reported-by: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/perf/imc-pmu.c

@@ -611,7 +611,8 @@ static int ppc_core_imc_cpu_online(unsigned int cpu)
 
 static int ppc_core_imc_cpu_offline(unsigned int cpu)
 {
-	unsigned int ncpu, core_id;
+	unsigned int core_id;
+	int ncpu;
 	struct imc_pmu_ref *ref;
 
 	/*