[binutils-gdb] Fix compile time warnings about using possibly uninitialised variables in rs6000-core.c.

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT f03265d9cda1f5f8df238efa9b7a20330e5711f1 ***

Author: Sam Thursfield <sam.thursfield@codethink.co.uk>
Branch: master
Commit: f03265d9cda1f5f8df238efa9b7a20330e5711f1

Fix compile time warnings about using possibly uninitialised variables in rs6000-core.c.

	* rs6000-core.c (CORE_NEW): Simplify macro when
	AIX_CORE_DUMPX_CORE and BFD64 are true to avoid compile warning.