Tidy up some C-isms.

Change-Id: I53b457cab9067369320457549071fc3e4c23c81b
diff --git a/src/zip_archive.cc b/src/zip_archive.cc
index 5e6b4eb..70a6261 100644
--- a/src/zip_archive.cc
+++ b/src/zip_archive.cc
@@ -378,12 +378,12 @@
   off_t search_start = file_length - read_amount;
 
   if (lseek(fd_, search_start, SEEK_SET) != search_start) {
-    LOG(WARNING) << "Zip: seek " << search_start << " failed: " << strerror(errno);
+    PLOG(WARNING) << "Zip: seek " << search_start << " failed";
     return false;
   }
   ssize_t actual = TEMP_FAILURE_RETRY(read(fd_, scan_buf.get(), read_amount));
   if (actual == -1) {
-    LOG(WARNING) << "Zip: read " << read_amount << " failed: " << strerror(errno);
+    PLOG(WARNING) << "Zip: read " << read_amount << " failed";
     return false;
   }