[PATCH] OS abstract out the random seed and value retrieval

This is pretty crappy on FreeBSD, the seed function doesn't seed the
state we want. But it works, so it'll have to suffice for now...
diff --git a/fio.h b/fio.h
index 89d7bf9..0b25bb8 100644
--- a/fio.h
+++ b/fio.h
@@ -169,8 +169,8 @@
 
 	char *ioscheduler;
 
-	struct drand48_data bsrange_state;
-	struct drand48_data verify_state;
+	os_random_state_t bsrange_state;
+	os_random_state_t verify_state;
 
 	int shm_id;
 
@@ -207,7 +207,7 @@
 	unsigned long long last_pos;
 	sem_t mutex;
 
-	struct drand48_data random_state;
+	os_random_state_t random_state;
 	unsigned long *file_map;
 	unsigned int num_maps;
 
@@ -237,7 +237,7 @@
 	unsigned int do_disk_util;
 	unsigned int override_sync;
 
-	struct drand48_data rwmix_state;
+	os_random_state_t rwmix_state;
 	struct timeval rwmix_switch;
 	int rwmix_ddir;