Fix regression script for async_io benchmarks (#11462)

Summary:
Fix regression script for async_io benchmarks to report right ops/sec and latency

Pull Request resolved: https://github.com/facebook/rocksdb/pull/11462

Test Plan: Verified locally

Reviewed By: anand1976

Differential Revision: D46031147

Pulled By: akankshamahajan15

fbshipit-source-id: 33ba587e6569ab2f834381ac2538e61da6876405

tools/regression_test.sh

@@ -113,7 +113,8 @@ DATA_FORMAT+="%9.0f,%10.0f,%10.0f,%10.0f,%10.0f,%10.0f,%5.0f,"
 DATA_FORMAT+="%5.0f,%5.0f,%5.0f" # time
 DATA_FORMAT+="\n"
 
-MAIN_PATTERN="$1""[[:blank:]]+:.*[[:blank:]]+([0-9\.]+)[[:blank:]]+ops/sec"
+# In case of async_io, $1 is benchmark_asyncio
+MAIN_PATTERN="${1%%_*}""[[:blank:]]+:.*[[:blank:]]+([0-9\.]+)[[:blank:]]+ops/sec"
 PERC_PATTERN="Percentiles: P50: ([0-9\.]+) P75: ([0-9\.]+) "
 PERC_PATTERN+="P99: ([0-9\.]+) P99.9: ([0-9\.]+) P99.99: ([0-9\.]+)"
 #==============================================================================