gomach: Resetting netif with cli doesn't return

[bergzand]

Description

A reset of the network interface via ifconfig 7 set state reset never returns.

Steps to reproduce the issue

Flash the examples/gnrc_networking_mac on a samr21-xpro send ifconfig 7 set state reset.

Expected results

The network interface is reset

Actual results

The node stops functioning

Versions

Installed compiler toolchains
-----------------------------
             native gcc: gcc (Gentoo 6.4.0-r1 p1.3) 6.4.0
      arm-none-eabi-gcc: arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 7-2018-q2-update) 7.3.1 20180622 (release) [ARM/embedded-7-branch revision 261907]              
                avr-gcc: avr-gcc (Gentoo 4.9.4 p1.0, pie-0.6.4) 4.9.4
       mips-mti-elf-gcc: missing
             msp430-gcc: missing
   riscv-none-embed-gcc: missing
                  clang: clang version 6.0.1 (tags/RELEASE_601/final)

Installed compiler libs
-----------------------
   arm-none-eabi-newlib: "3.0.0"
    mips-mti-elf-newlib: missing
riscv-none-embed-newlib: missing
               avr-libc: "2.0.0" ("20150208")

Installed development tools
---------------------------
                  cmake: cmake version 3.9.6
               cppcheck: Cppcheck 1.81
                doxygen: 1.8.14
                 flake8: 3.5.0 (mccabe: 0.6.1, pycodestyle: 2.3.1, pyflakes: 1.6.0) CPython 3.6.5 on Linux                                                                        
                    git: git version 2.18.1
                openocd: Open On-Chip Debugger 0.10.0
                 python: Python 3.6.5
                python2: Python 2.7.15
                python3: Python 3.6.5
             coccinelle: missing

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. If you want me to ignore this issue, please mark it with the "State: don't stale" label. Thank you for your contributions.

[miri64]

Might be related to #9656. We should see if this is fixed, after #9656 is fixed.