torture: Make kvm-check-branches.sh use --allcpus

Currently the kvm-check-branches.sh script calculates the number of CPUs
and passes this to the kvm.sh --cpus command-line argument.  This works,
but this commit saves a line by instead using the new kvm.sh --allcpus
command-line argument.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/rcutorture/bin/kvm-check-branches.sh

@@ -52,8 +52,7 @@ echo Results directory: $resdir/$ds
 KVM="`pwd`/tools/testing/selftests/rcutorture"; export KVM
 PATH=${KVM}/bin:$PATH; export PATH
 . functions.sh
-cpus="`identify_qemu_vcpus`"
-echo Using up to $cpus CPUs.
+echo Using all `identify_qemu_vcpus` CPUs.
 
 # Each pass through this loop does one command-line argument.
 for gitbr in $@
@@ -74,7 +73,7 @@ do
 		# Test the specified commit.
 		git checkout $i > $resdir/$ds/$idir/git-checkout.out 2>&1
 		echo git checkout return code: $? "(Commit $ntry: $i)"
-		kvm.sh --cpus $cpus --duration 3 --trust-make > $resdir/$ds/$idir/kvm.sh.out 2>&1
+		kvm.sh --allcpus --duration 3 --trust-make > $resdir/$ds/$idir/kvm.sh.out 2>&1
 		ret=$?
 		echo kvm.sh return code $ret for commit $i from branch $gitbr