s390/cpum_sf: Rework call to sf_disable()

Setup_pmc_cpu() function body consists of one single switch
statement with two cases PMC_INIT and PMC_RELEASE.
In both of these cases sf_disable() is invoked to turn off the
CPU Measurement sampling facility.
Move sf_disable() out of the switch statement.
No functional change.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

Author: Thomas Richter

arch/s390/kernel/perf_cpum_sf.c

@@ -559,16 +559,15 @@ static void setup_pmc_cpu(void *flags)
 {
 	struct cpu_hw_sf *cpuhw = this_cpu_ptr(&cpu_hw_sf);
 
+	sf_disable();
 	switch (*((int *)flags)) {
 	case PMC_INIT:
 		memset(cpuhw, 0, sizeof(*cpuhw));
 		qsi(&cpuhw->qsi);
 		cpuhw->flags |= PMU_F_RESERVED;
-		sf_disable();
 		break;
 	case PMC_RELEASE:
 		cpuhw->flags &= ~PMU_F_RESERVED;
-		sf_disable();
 		deallocate_buffers(cpuhw);
 		break;
 	}