kernel/profile.c: fix section mismatch warning

Impact: fix section mismatch warning in kernel/profile.c

Here, profile_nop function has been called from a non-init function
create_hash_tables(void). Which generetes a section mismatch warning.
Previously, create_hash_tables(void) was a init function. So, removing
__init from create_hash_tables(void) requires profile_nop to be
non-init.

This patch makes profile_nop function inline and fixes the
following warning:

 WARNING: vmlinux.o(.text+0x6ebb6): Section mismatch in reference from
 the function create_hash_tables() to the function
 .init.text:profile_nop()
 The function create_hash_tables() references
 the function __init profile_nop().
 This is often because create_hash_tables lacks a __init
 annotation or the annotation of profile_nop is wrong.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>