tests: Fix run-perfbench parsing "no matching params" case.

Signed-off-by: Angus Gratton <gus@projectgus.com>

tests/perf_bench/benchrun.py

@@ -15,7 +15,7 @@ def bm_run(N, M):
             cur_nm = nm
             param = p
     if param is None:
-        print(-1, -1, "no matching params")
+        print(-1, -1, "SKIP: no matching params")
         return
 
     # Run and time benchmark

tests/run-perfbench.py

@@ -187,7 +187,7 @@ def parse_output(filename):
         m = int(m.split("=")[1])
         data = []
         for l in f:
-            if l.find(": ") != -1 and l.find(": SKIP") == -1 and l.find("CRASH: ") == -1:
+            if ": " in l and ": SKIP" not in l and "CRASH: " not in l:
                 name, values = l.strip().split(": ")
                 values = tuple(float(v) for v in values.split())
                 data.append((name,) + values)