Use sys/random.h for getrandom() decl if present.

--- a/configure.in
+++ b/configure.in
@@ -6,7 +6,7 @@ AC_C_INLINE
 AC_HEADER_STDC
 #AC_PROG_INSTALL
 #CFLAGS="$CFLAGS -DHAVE_CONFIG_H"
-AC_CHECK_HEADERS([fallocate.h dlfcn.h unistd.h sys/xattr.h sys/acl.h sys/ioctl.h sys/reg.h endian.h linux/fs.h linux/fiemap.h stdint.h lzo/lzo1x.h openssl/evp.h linux/random.h malloc.h sched.h sys/statvfs.h])
+AC_CHECK_HEADERS([fallocate.h dlfcn.h unistd.h sys/xattr.h sys/acl.h sys/ioctl.h sys/reg.h endian.h linux/fs.h linux/fiemap.h stdint.h lzo/lzo1x.h openssl/evp.h linux/random.h sys/random.h malloc.h sched.h sys/statvfs.h])
 AC_CHECK_FUNCS([ffs ffsl basename fallocate64 splice getopt_long open64 pread pread64 lseek64 stat64 posix_fadvise posix_fadvise64 __builtin_prefetch htobe64 feof_unlocked getline getentropy getrandom posix_memalign valloc sched_yield fstatvfs __builtin_cpu_supports])
 AC_CHECK_LIB(dl,dlsym)
 AC_CHECK_LIB(fallocate,linux_fallocate64)
--- a/random.c
+++ b/random.c
@@ -23,6 +23,10 @@ typedef unsigned int __u32;
 #include <linux/random.h>
 #endif
 
+#ifdef HAVE_SYS_RANDOM_H
+#include <sys/random.h>
+#endif
+
 static void msleep(unsigned int msecs)
 {
 	struct timespec ts1, ts2;