ftrace: Fix unmatched locking in ftrace_regex_write()
ftrace: Fix unmatched locking in ftrace_regex_write()

When a command is passed to the set_ftrace_filter, then
the ftrace_regex_lock is still held going back to user space.

 # echo 'do_open : foo' > set_ftrace_filter
 (still holding ftrace_regex_lock when returning to user space!)

Signed-off-by: Li Zefan <5dc16b054e85ffba6c8d314d8e55ae95dcab12a5@cn.fujitsu.com>
LKML-Reference: <9482b3263efd2514f7650fc5638d9ac699d7c997@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs