Fix local variable 'arm_kernel_cli' referenced before assignment on ./run --emulator gem5

Fix #158

Author: cirosantilli

run

@@ -613,7 +613,7 @@ Extra options to append at the end of the emulator command line.
                         if self.env['kvm']:
                             cmd.extend(['--cpu-type', 'X86KvmCPU', LF])
                         if not self.env['baremetal']:
-                            cmd.extend(['--command-line', 'earlycon={} earlyprintk={} lpj=7999923 root=/dev/sda {}'.format(arm_kernel_cli, console, console, kernel_cli), LF])
+                            cmd.extend(['--command-line', 'earlycon={} earlyprintk={} lpj=7999923 root=/dev/sda {}'.format(console, console, kernel_cli), LF])
                     elif self.env['is_arm']:
                         if self.env['kvm']:
                             cmd.extend(['--cpu-type', 'ArmV8KvmCPU', LF])