cfg: turn a handful of parameter parsing errors into fatal (#554)

For parameters that require two values (`width, height` or `x, y`), if
the string fails to parse, turn into runtime failure.

src/spice2x/hooks/graphics/graphics_windowed.cpp

@@ -173,7 +173,7 @@ void graphics_load_windowed_parameters() {
             cfg::SCREENRESIZE->window_offset_x = result.first;
             cfg::SCREENRESIZE->window_offset_y = result.second;
         } else {
-            log_warning("graphics-windowed", "failed to parse -windowpos");
+            log_fatal("graphics-windowed", "failed to parse -windowpos");
         }
     }
 
@@ -202,7 +202,7 @@ void graphics_load_windowed_subscreen_parameters() {
             GRAPHICS_WSUB_WIDTH = result.first;
             GRAPHICS_WSUB_HEIGHT = result.second;
         } else {
-            log_warning("graphics-windowed", "failed to parse -wsubsize");
+            log_fatal("graphics-windowed", "failed to parse -iidxwsubsize / -sdvxwsubsize");
         }
     }
 
@@ -216,7 +216,7 @@ void graphics_load_windowed_subscreen_parameters() {
             GRAPHICS_WSUB_X = result.first;
             GRAPHICS_WSUB_Y = result.second;
         } else {
-            log_warning("graphics-windowed", "failed to parse -wsubpos");
+            log_fatal("graphics-windowed", "failed to parse -iidxwsubpos / -sdvxwsubpos");
         }
     }
 }