task/internal: fix coredump path split

task/internal: fix coredump path split

If the output is like

 core: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style, from 'systemd-sysusers', real uid: 0, effective uid: 0, real gid: 0, effective gid: 0, execfn: '/bin/systemd-sysusers', platform: 'x86_64'

then there is no space; first discard the ' and what follows, and
then discard anything after the space (if present!)

Signed-off-by: Sage Weil <sage@newdream.net>