util/vbuf: delete broken incompatible stride calc
What does this MR do and why?
util/vbuf: delete broken incompatible stride calc
this was accidentally duplicated from the conditional below,
except this one didn't have the buffer_stride_unaligned
caps check, which meant any 4-byte attrib which was
unaligned got marked for rewrites even on drivers
supporting unaligned strides
Fixes: 76725452239 ("gallium: move vertex stride to CSO")