mk: fix -share option error

mk: fix -share option error

The shared libraries built with the current makefile set produce static
libraries rather than actual shared objects.  This is due to several missing
options that are required to correctly build shared objects using ld, as well as
a mis-specified -share option (which should be -shared). Switching to the use of
CC rather than LD and fixing the -shared option corrects these problems and
builds the DSOs correctly.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>