torture: Make kvm-recheck-scf.sh tolerate qemu-cmd comments

The qemu-cmd file can contain comments that are not relevant to the
operation of kvm-recheck-scf.sh.  This commit therefore strips these
comments before looking for timing information.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/rcutorture/bin/kvm-recheck-scf.sh

@@ -25,7 +25,7 @@ if test -z "$nscfs"
 then
 	echo "$configfile ------- "
 else
-	dur="`sed -e 's/^.* scftorture.shutdown_secs=//' -e 's/ .*$//' < $i/qemu-cmd 2> /dev/null`"
+	dur="`grep -v '^#' $i/qemu-cmd | sed -e 's/^.* scftorture.shutdown_secs=//' -e 's/ .*$//' 2> /dev/null`"
 	if test -z "$dur"
 	then
 		rate=""