Explicit instantiation of a function template

Fixed annoying clang-tidy warning

Change-Id: I2a25aab6120aecf704f08d569ecc8cf632dea039
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/time/time.cc b/aos/time/time.cc
index fe8422b..0e02481 100644
--- a/aos/time/time.cc
+++ b/aos/time/time.cc
@@ -51,8 +51,8 @@
 
 #ifdef __linux__
 
-namespace std::this_thread {
-template <>
+namespace aos::this_thread {
+
 void sleep_until(const ::aos::monotonic_clock::time_point &end_time) {
   struct timespec end_time_timespec;
   ::std::chrono::seconds sec =
@@ -73,7 +73,7 @@
   } while (returnval != 0);
 }
 
-}  // namespace std::this_thread
+}  // namespace aos::this_thread
 
 #endif  // __linux__