Kill unused include of sched.h

Summary: These are the only includes of `sched.h` in Folly, and they really are unused:

Reviewed By: yfeldblum

Differential Revision: D4615501

fbshipit-source-id: 6a3a1aad7a91a92a322fd93d18e1284aa3f86b89

folly/Portability.h

@@ -24,10 +24,6 @@
 
 #include <folly/CPortability.h>
 
-#if FOLLY_HAVE_SCHED_H
- #include <sched.h>
-#endif
-
 // Unaligned loads and stores
 namespace folly {
 #if FOLLY_HAVE_UNALIGNED_ACCESS

folly/configure.ac

@@ -160,7 +160,7 @@ AM_PATH_PYTHON
 
 # Checks for header files.
 AC_HEADER_STDC
-AC_CHECK_HEADERS([fcntl.h features.h inttypes.h limits.h sched.h stdint.h stdlib.h string.h sys/time.h unistd.h mutex.h malloc.h bits/functexcept.h bits/c++config.h])
+AC_CHECK_HEADERS([fcntl.h features.h inttypes.h limits.h stdint.h stdlib.h string.h sys/time.h unistd.h mutex.h malloc.h bits/functexcept.h bits/c++config.h])
 
 AC_CHECK_HEADER(double-conversion/double-conversion.h, [], [AC_MSG_ERROR(
                 [Couldn't find double-conversion.h, please download from \

folly/detail/CacheLocality.h

@@ -16,7 +16,6 @@
 
 #pragma once
 
-#include <sched.h>
 #include <algorithm>
 #include <atomic>
 #include <cassert>

folly/test/CacheLocalityTest.cpp

@@ -18,7 +18,6 @@
 
 #include <folly/portability/GTest.h>
 
-#include <sched.h>
 #include <memory>
 #include <thread>
 #include <type_traits>