[PATCH v2 0/6] staging: sm750fb: fix error return values

This is v2 of the sm750fb error code fixes, split into one patch
per function as requested by Dan Carpenter.

Changes in v2:
- Split into one patch per function
- Propagate de_wait() error instead of hardcoding -EBUSY
- Each commit message describes caller behavior

Soham Kute (6):
11ca38f0ec63 staging: sm750fb: hw_sm750le_de_wait: return -ETIMEDOUT on timeout
28df828cc89b staging: sm750fb: sm750_hw_fillrect: propagate de_wait() error
2378ece78154 staging: sm750fb: sm750_hw_copyarea: propagate de_wait() error
85139ac8c7fe staging: sm750fb: sm750_hw_imageblit: propagate de_wait() error
9c2430311e23 staging: sm750fb: sw_i2c_write_byte: return -ETIMEDOUT on timeout
915599b01e9b staging: sm750fb: sm750_sw_i2c_init: return -EINVAL for invalid GPIO