x86emul: remove dead code

As of commit 989cdfa9b4 ("x86emul: don't special case fetching unsigned
8-bit immediates") the conditional being removed has been always false.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1856,9 +1856,6 @@ x86_emulate(
                     /* Special case in Grp3: test has immediate operand. */
                     ea.mem.off += (d & ByteOp) ? 1
                         : ((op_bytes == 8) ? 4 : op_bytes);
-                else if ( ext == ext_0f && ((b & 0xf7) == 0xa4) )
-                    /* SHLD/SHRD with immediate byte third operand. */
-                    ea.mem.off++;
                 break;
             case 1:
                 ea.mem.off += insn_fetch_type(int8_t);