Fix coccicheck warning which recommends to use memdup_user().

This patch fixes the following coccicheck warnings:

  drivers/firmware/efi/test/efi_test.c:269:8-15: WARNING opportunity for memdup_user

Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161018143318.15673-7-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Fix minor issue found by CoverityScan:

  520        kfree(name);
  CID 1358932 (#1 of 1): Uninitialized scalar variable (UNINIT)17.
  uninit_use: Using uninitialized value rv.
  521        return rv;
  522}

Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161018143318.15673-6-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Fix minor issue found by CoverityScan:

  CID 1358931 (#1 of 1): Uninitialized scalar variable (UNINIT)9.
  uninit_use: Using uninitialized value datasize.
  199        prev_datasize = datasize;
  200        status = efi.get_variable(name, vd, at, dz, data);

Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161018143318.15673-5-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20161018143318.15673-3-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This driver is used by the Firmware Test Suite (FWTS) for testing the UEFI
runtime interfaces readiness of the firmware.

This driver exports UEFI runtime service interfaces into userspace,
which allows to use and test UEFI runtime services provided by the
firmware.

This driver uses the efi.<service> function pointers directly instead of
going through the efivar API to allow for direct testing of the UEFI
runtime service interfaces provided by the firmware.

Details for FWTS are available from,
<https://wiki.ubuntu.com/FirmwareTestSuite>

Signed-off-by: Ivan Hu <ivan.hu@canonical.com>
Cc: joeyli <jlee@suse.com>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>