Fix some stupidness in ectool's comm_init() handling

ectool was checking for negative return values on comm_init(). It should
have been checking for nonzero. Or comm_init should have been returning
negative. Whatever. The ectool utility was supposed to be a quick-n-dirty
debugging tool, so it's not very well tested.

BUG=chromium:249218
BRANCH=none
TEST=manual

Fired up VM instance, tried old version and new version. Old version
coredumps, new version doesn't.

Change-Id: I0e27d78eead562a16ff826fb80de9e6b07476e12
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58712
Reviewed-by: Randall Spangler <rspangler@chromium.org>

util/ectool.c

@@ -3096,7 +3096,7 @@ int main(int argc, char *argv[])
 		exit(1);
 	}
 
-	if (comm_init() < 0) {
+	if (comm_init()) {
 		fprintf(stderr, "Couldn't find EC\n");
 		goto out;
 	}