Change string array emptiness test

Bug: 147488815
Test: Run dumpstate and check if HALs specified at "ro.dump.hals.extra"
property are included.

Change-Id: I57b2f2b28db08597eb384ff1d94db48d6f6c94cb
diff --git a/libs/dumputils/dump_utils.cpp b/libs/dumputils/dump_utils.cpp
index 2e14408..3ec4b3a 100644
--- a/libs/dumputils/dump_utils.cpp
+++ b/libs/dumputils/dump_utils.cpp
@@ -86,7 +86,7 @@
 
 static void read_extra_hals_to_dump_from_property() {
     // extra hals to dump are already filled
-    if (extra_hal_interfaces_to_dump.size() > 0) {
+    if (!extra_hal_interfaces_to_dump.empty()) {
         return;
     }
     std::string value = android::base::GetProperty("ro.dump.hals.extra", "");