arm64: avoid multiple evaluation of ptr in get_user/put_user()

arm64: avoid multiple evaluation of ptr in get_user/put_user()

get_user() is defined as a function macro in arm64, and trace_get_user()
calls it as followed:
     get_user(ch, ptr++);
Since the second parameter occurs twice in the definition, 'ptr++' is
unexpectedly evaluated twice and trace_get_user() will generate a bogus
string from user-provided one. As a result, some ftrace sysfs operations,
like "echo FUNCNAME > set_ftrace_filter," hit this case and eventually fail.
This patch fixes the issue both in get_user() and put_user().

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
[catalin.marinas@arm.com: added __user type annotation and s/optr/__p/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 1f65c13efef69b6dc908e588f91a133641d8475c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
Conflicts:
	arch/arm64/include/asm/uaccess.h