util: fix virBitmap allocation in virProcessInfoGetAffinity
util: fix virBitmap allocation in virProcessInfoGetAffinity

Bug: https://bugzilla.redhat.com/show_bug.cgi?id=878376

Found by coverity:
Error: REVERSE_INULL (CWE-476):
    libvirt-0.10.2/src/util/processinfo.c:141: deref_ptr: Directly
    dereferencing pointer "map".
    libvirt-0.10.2/src/util/processinfo.c:142: check_after_deref:
    Null-checking "map" suggests that it may be null, but it has already
    been dereferenced on all paths leading to the check.
(cherry picked from commit 7730257db30972a6f4db8d582b232b240b2a06b8)

mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2