ARC: clone: Ensure that @fn returns back to clone
ARC: clone: Ensure that @fn returns back to clone

This showed up due to longstanding test/unistd/clone failure where post
clone, the callback was not exiting and rather falling thru in into main
program.

Signed-off-by: Vineet Gupta <af669d95a4c0de051445d4cafdbb2c5c4a2838be@synopsys.com>
Signed-off-by: Bernhard Reutner-Fischer <ce1ac9e9ad16abccd7821f371ad381197b4768ac@gmail.com>

foss-for-synopsys-dwc-arc-processors/uClibc,kraj/uClibc,wbx-github/uclibc-ng,wbx-github/uclibc-ng,majek/uclibc-vx32,brgl/uclibc-ng,majek/uclibc-vx32,kraj/uclibc-ng,kraj/uClibc,wbx-github/uclibc-ng,kraj/uclibc-ng,kraj/uClibc,kraj/uclibc-ng,foss-for-synopsys-dwc-arc-processors/uClibc,brgl/uclibc-ng,brgl/uclibc-ng,wbx-github/uclibc-ng,foss-for-synopsys-dwc-arc-processors/uClibc,brgl/uclibc-ng,majek/uclibc-vx32,kraj/uClibc,foss-for-synopsys-dwc-arc-processors/uClibc,majek/uclibc-vx32,kraj/uclibc-ng