Drop might_sleep() calls from get_user() & co. This should fix the issue

in http://www.linux-mips.org/cgi-bin/mesg.cgi?a=linux-mips&i=200508171321.20094.Joshua.Wise%40sicortex.com

 and it's the right thing to do anyway because
it was inflating those functions way too much.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>