x86/platform/uv/BAU: Minor cleanup, make some local functions static

The functions handle_uv2_busy, uv_flush_send_and_wait and
find_another_by_swack are local to the source, so make them static.

Also remove normal_busy as it is no longer used.

Fixes various smatch warnings, such as:
"symbol 'find_another_by_swack' was not declared. Should it be static?"
"symbol 'handle_uv2_busy' was not declared. Should it be static?"

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Andrew Banman <abanman@hpe.com>
Cc: kernel-janitors@vger.kernel.org
Cc: Dimitri Sivanich <sivanich@sgi.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Link: http://lkml.kernel.org/r/20170704083129.10559-1-colin.king@canonical.com