primesieve.pc.in: Use CMAKE_INSTALL_FULL_BINDIR, etc.
primesieve.pc.in: Use CMAKE_INSTALL_FULL_BINDIR, etc.

Previously the CMAKE_INSTALL_PREFIX was incorrectly prepended to
CMAKE_INSTALL_BINDIR even if the latter was already an absolute path.
Instead, use the correctly resolved absolute path variables that CMake
already provides.

Signed-off-by: Anders Kaseorg <087231934ba8fcf78bc142ce37d193b895ac03c4@mit.edu>

kimwalisch/primesieve,kimwalisch/primesieve,kimwalisch/primesieve