s390/cpum_sf: Remove unnecessary check for pending SDBs

In interrupt handling the function extend_sampling_buffer()
is called after checking for a possibly extension.
This check is not necessary as the called function itself
performs this check again.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/kernel/perf_cpum_sf.c

@@ -952,7 +952,6 @@ static void cpumsf_pmu_enable(struct pmu *pmu)
 			 * buffer extents
 			 */
 			sfb_account_overflows(cpuhw, hwc);
-			if (sfb_has_pending_allocs(&cpuhw->sfb, hwc))
 			extend_sampling_buffer(&cpuhw->sfb, hwc);
 		}
 		/* Rate may be adjusted with ioctl() */