perf tests: Rename thread-mg-share to thread-maps-share

One more step in merging 'struct maps' with 'struct map_groups'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-naxsl3g4ou3fyxb8l8e0pn5e@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/Build

@@ -27,7 +27,7 @@ perf-y += wp.o
 perf-y += task-exit.o
 perf-y += sw-clock.o
 perf-y += mmap-thread-lookup.o
-perf-y += thread-mg-share.o
+perf-y += thread-maps-share.o
 perf-y += switch-tracking.o
 perf-y += keep-tracking.o
 perf-y += code-reading.o