intel/disasm: Remove duplicate variable reg_file
What does this MR do and why?
intel/disasm: Remove duplicate variable reg_file
Fix defects reported by Coverity Scan.
Evaluation order violation (EVALUATION_ORDER)
write_write_typo: In reg_file = reg_file = brw_inst_dpas_3src_dst_reg_file(devinfo, inst),
reg_file is written twice with the same value.
Fixes: 1c92dad5cb7 ("intel/disasm: Disassembly support for DPAS")
Signed-off-by: Vinson Lee <vlee@freedesktop.org>