bpftool: Add SPDX tags to RST documentation files

Most files in the kernel repository have a SPDX tags. The files that
don't have such a tag (or another license boilerplate) tend to fall
under the GPL-2.0 license. In the past, bpftool's Makefile (for example)
has been marked as GPL-2.0 for that reason, when in fact all bpftool is
dual-licensed.

To prevent a similar confusion from happening with the RST documentation
files for bpftool, let's explicitly mark all files as dual-licensed.

Signed-off-by: Quentin Monnet <[e-mail]>
Signed-off-by: Daniel Borkmann <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/bpftool/Documentation/Makefile

···
 man8: $(DOC_MAN8)
 
 RST2MAN_DEP := $(shell command -v rst2man 2>/dev/null)
-RST2MAN_OPTS += --verbose
+RST2MAN_OPTS += --verbose --strip-comments
 
 list_pages = $(sort $(basename $(filter-out $(1),$(MAN8_RST))))
 see_also = $(subst " ",, \

tools/bpf/bpftool/Documentation/bpftool-btf.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-btf
 ================

tools/bpf/bpftool/Documentation/bpftool-cgroup.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-cgroup
 ================

tools/bpf/bpftool/Documentation/bpftool-feature.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ===============
 bpftool-feature
 ===============

tools/bpf/bpftool/Documentation/bpftool-gen.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-gen
 ================

tools/bpf/bpftool/Documentation/bpftool-iter.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ============
 bpftool-iter
 ============

tools/bpf/bpftool/Documentation/bpftool-link.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-link
 ================

tools/bpf/bpftool/Documentation/bpftool-map.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-map
 ================

tools/bpf/bpftool/Documentation/bpftool-net.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-net
 ================

tools/bpf/bpftool/Documentation/bpftool-perf.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-perf
 ================

tools/bpf/bpftool/Documentation/bpftool-prog.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 bpftool-prog
 ================

tools/bpf/bpftool/Documentation/bpftool-struct_ops.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ==================
 bpftool-struct_ops
 ==================

tools/bpf/bpftool/Documentation/bpftool.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 ================
 BPFTOOL
 ================

tools/bpf/bpftool/Documentation/common_options.rst

···
+.. SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+
 -h, --help
 	  Print short help message (similar to **bpftool help**).