Fix size of monoblack_pal array, code uses 16 values unconditionally.

Patch by Daniel Verkamp [daniel drv nu].

Originally committed as revision 26088 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/pcxenc.c

@@ -33,7 +33,7 @@ typedef struct PCXContext {
     AVFrame picture;
 } PCXContext;
 
-static const uint32_t monoblack_pal[] = { 0x000000, 0xFFFFFF };
+static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
 
 static av_cold int pcx_encode_init(AVCodecContext *avctx)
 {