genesys: Switch session startx and starty to unsigned

The sources and destinations are integer in most cases for these
variables.

backend/genesys/gl843.cpp

@@ -1043,11 +1043,7 @@ static void gl843_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
                                          Genesys_Register_Set* reg, unsigned int exposure,
                                          const ScanSession& session)
 {
-    DBG_HELPER_ARGS(dbg, "exposure=%d, used_res=%d, start=%f, pixels=%d, channels=%d, depth=%d, "
-                         "ccd_size_divisor=%d",
-                    exposure, session.output_resolution, session.params.startx,
-                    session.optical_pixels, session.params.channels, session.params.depth,
-                    session.ccd_size_divisor);
+    DBG_HELPER_ARGS(dbg, "exposure=%d", exposure);
     unsigned int dpihw;
   unsigned int tgtime;          /**> exposure time multiplier */
   GenesysRegister *r;
@@ -2370,8 +2366,8 @@ void CommandSetGl843::init_regs_for_scan(Genesys_Device* dev, const Genesys_Sens
     ScanSession session;
     session.params.xres = dev->settings.xres;
     session.params.yres = dev->settings.yres;
-    session.params.startx = start;
-    session.params.starty = move;
+    session.params.startx = static_cast<unsigned>(start);
+    session.params.starty = static_cast<unsigned>(move);
     session.params.pixels = dev->settings.pixels;
     session.params.requested_pixels = dev->settings.requested_pixels;
     session.params.lines = dev->settings.lines;

backend/genesys/low.cpp

@@ -2517,7 +2517,7 @@ void debug_dump(unsigned level, const SetupParams& params)
         "Pixels per line (requested) : %u\n"
         "Depth : %u\n"
         "Channels : %u\n"
-        "Start position X/Y : %g / %g\n"
+        "Start position X/Y : %u / %u\n"
         "Scan mode : %d\n"
         "Color filter : %d\n"
         "Flags : %x\n",

backend/genesys/settings.h

@@ -114,9 +114,9 @@ struct SetupParams {
     // resolution in y direction
     unsigned yres = NOT_SET;
     // start pixel in X direction, from dummy_pixel + 1
-    float startx = -1;
+    unsigned startx = NOT_SET;
     // start pixel in Y direction, counted according to base_ydpi
-    float starty = -1;
+    unsigned starty = NOT_SET;
     // the number of pixels in X direction. Note that each logical pixel may correspond to more
     // than one CCD pixel, see CKSEL and GenesysSensor::ccd_pixels_per_system_pixel()
     unsigned pixels = NOT_SET;
@@ -153,7 +153,7 @@ struct SetupParams {
 
     void assert_valid() const
     {
-        if (xres == NOT_SET || yres == NOT_SET || startx < 0 || starty < 0 ||
+        if (xres == NOT_SET || yres == NOT_SET || startx == NOT_SET || starty == NOT_SET ||
             pixels == NOT_SET || lines == NOT_SET ||depth == NOT_SET || channels == NOT_SET ||
             scan_method == static_cast<ScanMethod>(NOT_SET) ||
             scan_mode == static_cast<ScanColorMode>(NOT_SET) ||