Fix mingw32 build errors like
/src/qemu/ui/vnc-enc-tight.c: In function 'tight_detect_smooth_image24':
/src/qemu/ui/vnc-enc-tight.c:119: error: 'uint' undeclared (first use in this function)
Replace 'uint' with proper 'unsigned int'.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>