Remove -DSK_XML from dm and nanobench.

Specifying -DSK_XML is equivelent to

    #define SK_XML 1

However, we are also specifying

    #define SK_XML

in the generated SkUserConfig.h. As a result, every file built for dm
and nanobench spews

    warning: 'SK_XML' macro redefined [-Wmacro-redefined]

This CL removes -DSK_XML from the dm and nanobench Android.mk files to
avoid this. SK_XML will now come from the generated SkUserConfig.h.

Test: built and observed much less warning spew.

Change-Id: I8c97317344d1f124fa6c8a70ede5cd8aee59ec17
2 files changed