[mlir] Fix a warning about an extraneous semicolon

This patch fixes:

  mlir/lib/Dialect/XeGPU/IR/XeGPUOps.cpp:58:2: error: extra ';'
  outside of a function is incompatible with C++98
  [-Werror,-Wc++98-compat-extra-semi]

Author: kazutakahirata

mlir/lib/Dialect/XeGPU/IR/XeGPUOps.cpp

@@ -55,7 +55,7 @@ static int64_t getRankOf(Value val) {
   if (auto ty = llvm::dyn_cast<ShapedType>(type))
     return ty.getRank();
   return 0;
-};
+}
 
 static bool isReadHintOrNone(const CachePolicyAttr &attr) {
   if (!attr)