gcore: quote PKGVERSION

Same as 3bed686102cb14552d2ed1b83336453d7ce0dd47. I didn't hit an issue
here -- I think because my /bin/sh is dash and gdb-add-index has a /bin/sh
shebang, while gcore uses bash, but it's still worth fixing (we certainly
do NOT want this to be an array).

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32325
1 file changed