rename HAVE_PREADV to CONFIG_PREADV

Signed-off-by: NJuan Quintela <quintela@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

configure

@@ -1736,7 +1736,7 @@ if test "$iovec" = "yes" ; then
   echo "#define HAVE_IOVEC 1" >> $config_host_h
 fi
 if test "$preadv" = "yes" ; then
-  echo "#define HAVE_PREADV 1" >> $config_host_h
+  echo "#define CONFIG_PREADV 1" >> $config_host_h
 fi
 if test "$fdt" = "yes" ; then
   echo "CONFIG_FDT=y" >> $config_host_mak

posix-aio-compat.c

@@ -33,7 +33,7 @@ static int cur_threads = 0;
 static int idle_threads = 0;
 static TAILQ_HEAD(, qemu_paiocb) request_list;
 
-#ifdef HAVE_PREADV
+#ifdef CONFIG_PREADV
 static int preadv_present = 1;
 #else
 static int preadv_present = 0;
@@ -102,7 +102,7 @@ static size_t handle_aiocb_ioctl(struct qemu_paiocb *aiocb)
 	return aiocb->aio_nbytes;
 }
 
-#ifdef HAVE_PREADV
+#ifdef CONFIG_PREADV
 
 static ssize_t
 qemu_preadv(int fd, const struct iovec *iov, int nr_iov, off_t offset)