Fix build error due to unsigned compare >= 0 in r263008 (NFC)

Fixes error from building with clang:

/usr/local/google/home/tejohnson/llvm/llvm_15/lib/Target/AMDGPU/InstPrinter/AMDGPUInstPrinter.cpp:407:12:
error: comparison of unsigned expression >= 0 is always true
[-Werror,-Wtautological-compare]
  if ((Imm >= 0x000) && (Imm <= 0x0ff)) {
         ~~~ ^  ~~~~~

llvm-svn: 263014