MFC r315595,r315603:

r315595:

Remove a commented out line before kvm_getprocs(3)

The commented out return value for kvm_getprocs(3) was misleading -- the
uncommented line is correct.

No content change

r315603:

kvm_close(3): return error instead of blindly returning 0

error is the accumulated error from previous close(2) calls.

This bug has been present since the libcall's import from 4.4BSD
Lite (r1573).

Noticed by: vangyzen (D10022)
Relnotes: yes