[autotest] make Suite.find_and_parse_tests less spammy

The autoserv.DEBUG logs for a suite job contain ~750 lines of
"Considering XXXXXXXXXX", for each control file that gets filtered through
the test-matching predicate. This makes the log unneccesarily long, hard
to read and obscures a lot of much more useful information.

This CL replaces the individual "Considering XXXX" messages with a
single message summarizing the number of control files that were parsed.

BUG=None
TEST=Ran suite in local autotest. Hundreds of "Considering XXX" lines
were absent.

Change-Id: I6a3bed1e9637630b3f1e26bf08e6adb48e50810d
Reviewed-on: https://gerrit.chromium.org/gerrit/57520
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
Reviewed-by: Scott Zawalski <scottz@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
1 file changed