Upscale progress bar fix

[ring-c]

Small fix of a number of tiles processed in upscaling, so progress bar works correctly.
Logs before fix:

upscaler.cpp:45   - upscaling from (544 x 960) to (2176 x 3840)
...
ggml_extend.hpp:461  - processing 56 tiles
  |==================================================| 56/56 - 12.35it/s
  |==================================================| 60/56 - 12.35it/supscaler.cpp:75   - input_image_tensor upscaled, taking 5.15s

Logs after fix:

ggml_extend.hpp:458  - processing 60 tiles
  |==================================================| 60/60 - 12.05it/s
upscaler.cpp:75   - input_image_tensor upscaled, taking 5.13s

[leejet]

Thank you for your contribution.