kaiser: user_map __kprobes_text too

In 3.2 (and earlier, and up to 3.15) Kaiser needs to user_map the
__kprobes_text as well as the __entry_text: entry_64.S places some
vital functions there, so without this you very soon triple-fault.
Many thanks to Jiri Kosina for pointing me in this direction.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc arch/x86/mm/kaiser.c
Simple merge