Revert "base: make boot_clock work on host linux, hide it on non-linux."

This reverts commit ae29339ca138648eeaee68f801feb02d85ee2abf, which broke the darwin build.

Change-Id: Ib33e2dab197532f04944cb12151002e9219b1bb5
diff --git a/base/chrono_utils_test.cpp b/base/chrono_utils_test.cpp
index 1f1ce15..057132d 100644
--- a/base/chrono_utils_test.cpp
+++ b/base/chrono_utils_test.cpp
@@ -16,7 +16,6 @@
 
 #include "android-base/chrono_utils.h"
 
-#include <err.h>
 #include <time.h>
 
 #include <chrono>
@@ -26,12 +25,9 @@
 namespace android {
 namespace base {
 
-#if defined(__linux__)
 std::chrono::seconds GetBootTimeSeconds() {
   struct timespec now;
-  if (clock_gettime(CLOCK_BOOTTIME, &now) != 0) {
-    err(1, "clock_gettime failed");
-  }
+  clock_gettime(CLOCK_BOOTTIME, &now);
 
   auto now_tp = boot_clock::time_point(std::chrono::seconds(now.tv_sec) +
                                        std::chrono::nanoseconds(now.tv_nsec));
@@ -45,7 +41,6 @@
       std::chrono::duration_cast<std::chrono::seconds>(boot_clock::now().time_since_epoch());
   EXPECT_EQ(now, boot_seconds);
 }
-#endif  // defined(__linux__)
 
 }  // namespace base
-}  // namespace android
+}  // namespace android
\ No newline at end of file