torture: Add "ERROR" diagnostic for testing kernel-build output

Some recent kernel-build failures have featured "ERROR", so this commit
adds it to the list checked by kvm-build.sh.

Signed-off-by: Paul E. McKenney <[email protected]>
Signed-off-by: Neeraj Upadhyay (AMD) <[email protected]>

Author: paulmckrcu

tools/testing/selftests/rcutorture/bin/kvm-build.sh

@@ -44,7 +44,7 @@ fi
 ncpus="`getconf _NPROCESSORS_ONLN`"
 make -j$((2 * ncpus)) $TORTURE_KMAKE_ARG > $resdir/Make.out 2>&1
 retval=$?
-if test $retval -ne 0 || grep "rcu[^/]*": < $resdir/Make.out | grep -E -q "Stop|Error|error:|warning:" || grep -E -q "Stop|Error|error:" < $resdir/Make.out
+if test $retval -ne 0 || grep "rcu[^/]*": < $resdir/Make.out | grep -E -q "Stop|ERROR|Error|error:|warning:" || grep -E -q "Stop|ERROR|Error|error:" < $resdir/Make.out
 then
 	echo Kernel build error
 	grep -E "Stop|Error|error:|warning:" < $resdir/Make.out