nsvdec: change 2 commented assert() to av_assert()

they keep showing up if i grep for non av assert()
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/nsvdec.c

@@ -100,8 +100,8 @@ struct NSVs_header {
     uint32_t chunk_tag; /* 'NSVs' */
     uint32_t v4cc;      /* or 'NONE' */
     uint32_t a4cc;      /* or 'NONE' */
-    uint16_t vwidth;    /* assert(vwidth%16==0) */
-    uint16_t vheight;   /* assert(vheight%16==0) */
+    uint16_t vwidth;    /* av_assert(vwidth%16==0) */
+    uint16_t vheight;   /* av_assert(vheight%16==0) */
     uint8_t framerate;  /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
     uint16_t unknown;
 };