Wrong format specification

[yurivict]

clang-6 prints this warning:

eps_img.c:122:34: warning: cc -O1 -ansi -Iclib -DOPENGL_SUPPORT -I/glut/include -DIMAGE_SUPPORT -DJPEG_SUPPORT -I/jpeg -DPNG_SUPPORT -I/libpng -I/zlib -DGIF_SUPPORT -I/gd -fno-omit-frame-pointer -isystem /usr/local/include  -c -o jpeg_img.o jpeg_img.c
format specifies type 'unsigned short' but the argument has type 'char' [-Wformat]
      fprintf (outfile, "%02hx", *pix++);
                         ~~~~~   ^~~~~~
                         %02hhx