Stop duplicating <linux/capabilities.h>.

This doesn't help the person who wants CAP_BPF, but we can fix that
better by adding it to our stale glibc (and our future switch to musl
will mean we'll never have similar problems again).

I think this just dates from when we still supported building the OS on
darwin, but those days are long gone, and I think this hack can be put
to rest now...

Test: treehugger
Change-Id: I3c2e56c68a5b00c1ad0aed422c6ce60886063f50
diff --git a/libcutils/Android.bp b/libcutils/Android.bp
index 55a8694..8ae7d9e 100644
--- a/libcutils/Android.bp
+++ b/libcutils/Android.bp
@@ -171,11 +171,15 @@
                 "libasync_safe",
             ],
         },
+        linux: {
+            srcs: [
+                "canned_fs_config.cpp",
+                "fs_config.cpp",
+            ],
+        },
         not_windows: {
             srcs: libcutils_nonwindows_sources + [
                 "ashmem-host.cpp",
-                "canned_fs_config.cpp",
-                "fs_config.cpp",
                 "trace-host.cpp",
             ],
         },
@@ -201,8 +205,6 @@
             srcs: libcutils_nonwindows_sources + [
                 "android_reboot.cpp",
                 "ashmem-dev.cpp",
-                "canned_fs_config.cpp",
-                "fs_config.cpp",
                 "klog.cpp",
                 "partition_utils.cpp",
                 "qtaguid.cpp",