use standard integer types, not linux ones

--- frontend/main.c
+++ frontend/main.c
@@ -440,13 +440,13 @@
     MP4TrackId MP4track = 0;
     unsigned int ntracks = 0, trackno = 0;
     unsigned int ndiscs = 0, discno = 0;
-    u_int8_t compilation = 0;
+    uint8_t compilation = 0;
     const char *artist = NULL, *title = NULL, *album = NULL, *year = NULL,
       *genre = NULL, *comment = NULL, *writer = NULL;
-    u_int8_t *art = NULL;
-    u_int64_t artSize = 0;
-    u_int64_t total_samples = 0;
-    u_int64_t encoded_samples = 0;
+    uint8_t *art = NULL;
+    uint64_t artSize = 0;
+    uint64_t total_samples = 0;
+    uint64_t encoded_samples = 0;
     unsigned int delay_samples;
     unsigned int frameSize;
 #endif
@@ -647,7 +647,7 @@
         FILE *artFile = fopen(optarg, "rb");
 
         if(artFile) {
-            u_int64_t r;
+            uint64_t r;
 
             fseek(artFile, 0, SEEK_END);
         artSize = ftell(artFile);
@@ -1112,7 +1112,7 @@
             if (bytesWritten > 0)
             {
 #ifdef HAVE_LIBMP4V2
-                u_int64_t samples_left = total_samples - encoded_samples + delay_samples;
+                uint64_t samples_left = total_samples - encoded_samples + delay_samples;
                 MP4Duration dur = samples_left > frameSize ? frameSize : samples_left;
                 MP4Duration ofs = encoded_samples > 0 ? 0 : delay_samples;