Add missing math and sys imports in llava_trainer.py

[Mr-Neutr0n]

Summary

• Adds import math and import sys to llava/train/llava_trainer.py
• _inner_training_loop uses math.ceil() and sys.maxsize but neither module was imported
• Training crashes with NameError: name 'math' is not defined

Related Issue

Fixes #504

Test plan

• Run training command to verify no more NameError
• Verify training proceeds normally

[Mr-Neutr0n]

hey, just checking in. this adds missing math and sys imports in llava_trainer.py that cause NameError at runtime. one-liner fix

[Mr-Neutr0n]

Friendly bump! Let me know if there's anything I should update or improve to help move this forward.

[Mr-Neutr0n]

This is still missing a reviewer. The change is straightforward -- adding the math and sys imports that llava_trainer.py already uses (for example, math.isnan checks on loss values). Happy to rebase if needed.