util: add a streq helper

This is a little easier to read than strcmp.

Bug: None
Test: unittests pass
Change-Id: Idccb94c2cce84b11bd9bb9eeab699254baef529d
diff --git a/bpf.c b/bpf.c
index d8bf46c..6fbe9b0 100644
--- a/bpf.c
+++ b/bpf.c
@@ -362,7 +362,7 @@
 	}
 	end = begin + labels->count;
 	for (id = 0; begin < end; ++begin, ++id) {
-		if (!strcmp(label, begin->label)) {
+		if (streq(label, begin->label)) {
 			return id;
 		}
 	}