FROMGIT: samples/hw_breakpoint: drop use of kallsyms_lookup_name()

The 'data_breakpoint' test code is the only modular user of
kallsyms_lookup_name(), which was exported as part of fixing the test in
f60d24d2 ("hw-breakpoints: Fix broken hw-breakpoint sample module").

In preparation for un-exporting this symbol, switch the test over to using
__symbol_get(), which can be used to place breakpoints on exported
symbols.

Bug: 149978696
Change-Id: I589142af97a34484f9fa551b934148f445b33243
Link: http://lkml.kernel.org/r/20200221114404.14641-3-will@kernel.org


Signed-off-by: Will Deacon <will@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit e108898157d888c827a7176e02648cc3bd87025b
 https://github.com/hnaz/linux-mm.git

 master)
Signed-off-by: Quentin Perret <qperret@google.com>