MdeModulePkg/Core/Dxe: log informative memprotect msgs at DEBUG_INFO level

MdeModulePkg/Core/Dxe: log informative memprotect msgs at DEBUG_INFO level

In commit 7eb927db3e25 ("MdeModulePkg/DxeCore: implement memory protection
policy", 2017-02-24), we added two informative messages with the
InitializeDxeNxMemoryProtectionPolicy() function:

> InitializeDxeNxMemoryProtectionPolicy: applying strict permissions to
> active memory regions

and

> InitializeDxeNxMemoryProtectionPolicy: applying strict permissions to
> inactive memory regions

The messages don't report errors or warnings, thus downgrade their log
masks from DEBUG_ERROR to DEBUG_INFO.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1520485
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Star Zeng <star.zeng@intel.com>