common/fio: ignore fio messages about random generator selection

The latest fio after the commit 1d282baecd68 ("fio: make sure that child
process output is comitted") often prints the warning messages about
random generator selection:

    fio: file test.0.0 exceeds 32-bit tausworthe random generator.
    fio: Switching to tausworthe64. Use the random_generator= option to get rid of this warning.

This causes fio output parse failure at the test case block/004. To
avoid the failure, ignore the messages.

Signed-off-by: Shin'ichiro Kawasaki <[email protected]>

Author: kawasaki

common/fio

@@ -229,7 +229,9 @@ _fio_perf_report() {
 			echo "_fio_perf: too many terse lines" >&2
 			return
 		fi
-	} <"$TMPDIR/fio_perf"
+		# Fio often spits out message about random generator switch from
+		# tausworthe to tausworthe64. Ignore the message.
+	} < <(grep --invert-match tausworthe "$TMPDIR/fio_perf")
 
 	for name in "${FIO_PERF_FIELDS[@]}"; do
 		field="${FIO_TERSE_FIELDS["$name"]}"