gsm 08.08: Fix some u_int8_t -> uint8_t

This breaks the ARM build in osmocom-bb. Besides uint??_t seems to
be the preferred type in osmocore. (coming from stdint.h vs sys/types.h)

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/include/osmocore/protocol/gsm_08_08.h b/include/osmocore/protocol/gsm_08_08.h
index 9c29ba9..6b8f935 100644
--- a/include/osmocore/protocol/gsm_08_08.h
+++ b/include/osmocore/protocol/gsm_08_08.h
@@ -30,14 +30,14 @@
 };
 
 struct bssmap_header {
-	u_int8_t type;
-	u_int8_t length;
+	uint8_t type;
+	uint8_t length;
 } __attribute__((packed));
 
 struct dtap_header {
-	u_int8_t type;
-	u_int8_t link_id;
-	u_int8_t length;
+	uint8_t type;
+	uint8_t link_id;
+	uint8_t length;
 } __attribute__((packed));