### What this PR does / why we need it?
change self.head_size to self.rotary_dim.
only the rotary part is processed here, the dimension should be rotary_dim.
Fix bug #6060
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Only a small section of code was modified to adjust the parameters, and
all standard tests were passed.
- vLLM version: v0.14.1
- vLLM main:
dc917cceb8
Signed-off-by: fengshi666 <fengshi666@adsl-99-12-210-25.dsl.hstntx.sbcglobal.net>
Co-authored-by: fengshi666 <fengshi666@adsl-99-12-210-25.dsl.hstntx.sbcglobal.net>