host lib: include <sys/types.h> for ssize_t

In uClibc neither <stdio.h> nor <strings.h> defines ssize_t.

Change-Id: I7fb6a0f51eae76062784952beb42298c486461b5
Signed-off-by: Alex Suykov <alex.suykov@gmail.com>
Reviewed-on: https://chromium-review.googlesource.com/320472
Commit-Ready: Stefan Reinauer <reinauer@google.com>
Tested-by: Stefan Reinauer <reinauer@google.com>
Reviewed-by: Stefan Reinauer <reinauer@google.com>
diff --git a/host/lib/fmap.c b/host/lib/fmap.c
index c95338d..347eef1 100644
--- a/host/lib/fmap.c
+++ b/host/lib/fmap.c
@@ -6,6 +6,7 @@
 
 #include <stdio.h>
 #include <string.h>
+#include <sys/types.h>
 
 #include "fmap.h"